Targeting lactate transport suppresses in vivo breast tumour growth

Background: Most cancers, including breast cancer, have high rates of glucose consumption, associated with lactate production, a process referred as “Warburg effect”. Acidification of the tumour microenvironment by lactate extrusion, performed by lactate transporters (MCTs), is associated with higher cell proliferation, migration, invasion, angiogenesis and increased cell survival. Previously, we have described MCT1 up-regulation in breast carcinoma samples and demonstrated the importance of in vitro MCT inhibition. In this study, we performed siRNA knockdown of MCT1 and MCT4 in basal-like breast cancer cells in both normoxia and hypoxia conditions to validate the potential of lactate transport inhibition in breast cancer treatment. Results: The effect of MCT knockdown was evaluated on lactate efflux, proliferation, cell biomass, migration and invasion and induction of tumour xenografts in nude mice. MCT knockdown led to a decrease in in vitro tumour cell aggressiveness, with decreased lactate transport, cell proliferation, migration and invasion and, importantly, to an inhibition of in vivo tumour formation and growth. Conclusions: This work supports MCTs as promising targets in cancer therapy, demonstrates the contribution of MCTs to cancer cell aggressiveness and, more importantly, shows, for the first time, the disruption of in vivo breast tumour growth by targeting lactate transport.

Upper Eyelid Reconstruction With a Horizontal V-Y Myotarsocutaneous Advancement Flap

Upper eyelid tumours, particularly basal cell carcinomas, are relatively frequent. Surgical ablation of these lesions creates defects of variable complexity. Although several options are available for lower eyelid reconstruction, fewer surgical alternatives exist for upper eyelid reconstruction. Large defects of this region are usually reconstructed with two-step procedures. In 1997, Okada et al. described a horizontal V-Y myotarsocutaneous advancement flap for reconstruction of a large upper eyelid defect in a single operative time. However, no further studies were published regarding the use of this particular flap in upper eyelid reconstruction. In addition, this flap is not described in most plastic surgery textbooks. The authors report here their experience of 16 cases of horizontal V-Y myotarsocutaneous advancement flaps used to reconstruct full-thickness defects of the upper eyelid after tumour excision. The tumour histological types were as follows: 12 basal cell carcinomas, 2 cases of squamous cell carcinomas, 1 case of sebaceous cell carcinoma and 1 of malignant melanoma. This technique allowed closure of defects of up to 60% of the eyelid width. None of the flaps suffered necrosis. The mean operative time was 30 min. No additional procedures were necessary as good functional and cosmetic results were achieved in all cases. No recurrences were noted. In this series, the horizontal V-Y myotarsocutaneous advancement flap proved to be a technically simple, reliable and expeditious option for reconstruction of full-thickness upper eyelid defects (as wide as 60% of the eyelid width) in a single operative procedure. In the future this technique may become the preferential option for such defects.

Targeting lactate transport suppresses in vivo breast tumour growth.

BACKGROUND Most cancers, including breast cancer, have high rates of glucose consumption, associated with lactate production, a process referred as "Warburg effect". Acidification of the tumour microenvironment by lactate extrusion, performed by lactate transporters (MCTs), is associated with higher cell proliferation, migration, invasion, angiogenesis and increased cell survival. Previously, we have described MCT1 up-regulation in breast carcinoma samples and demonstrated the importance of in vitro MCT inhibition. In this study, we performed siRNA knockdown of MCT1 and MCT4 in basal-like breast cancer cells in both normoxia and hypoxia conditions to validate the potential of lactate transport inhibition in breast cancer treatment. RESULTS The effect of MCT knockdown was evaluated on lactate efflux, proliferation, cell biomass, migration and invasion and induction of tumour xenografts in nude mice. MCT knockdown led to a decrease in in vitro tumour cell aggressiveness, with decreased lactate transport, cell proliferation, migration and invasion and, importantly, to an inhibition of in vivo tumour formation and growth. CONCLUSIONS This work supports MCTs as promising targets in cancer therapy, demonstrates the contribution of MCTs to cancer cell aggressiveness and, more importantly, shows, for the first time, the disruption of in vivo breast tumour growth by targeting lactate transport.

Descriptive epidemiology of skin cancer in the Swiss Canton of Vaud.

Incidence registration and survival data for non-melanocytic skin neoplasms and cutaneous melanoma have been abstracted from the population-based system of the Cancer Registry of the Swiss Canton of Vaud, which has been operating in a particularly favourable environment, since the large majority of cutaneous lesions resected in the area are examined by a pathologist. Among the 5,712 cases registered, 66.7% were basal-cell carcinomas, 20.6% squamous-cell cancers, 9.3% cutaneous melanomas and 3.4% other miscellaneous histological types. The distribution by histological type did not differ appreciably in the 2 sexes, but there were marked inter-sex differences as regards anatomical site. In both sexes, head and neck was by far the commonest localization for non-melanomatous neoplasms (69 to 81% of all incident cases), followed by trunk for basal-cell cancers (18% in males, 15% in females) and upper limb for squamous-cell (10% in males, 17% in females). The distribution of skin melanomas differed considerably between the 2 sexes, by far the commonest site being the trunk for males (45% of cases) and lower limbs for females (40%), followed by head and neck (22% in both sexes). Incidence rates for both basal- and squamous-cell cancers increased with age, and rates were higher in males for each localization except the lower limb. In contrast, incidence for melanoma was higher in females, and incidence rates did not increase with age above 55 years for all sites except head and neck. This can be interpreted in terms of cohort effect, since mortality from melanoma has substantially increased in Switzerland across subsequent birth cohorts. Although this study is essentially descriptive, accurate inspection of these data provides some support for the major aetiological hypotheses of skin carcinogenesis, i.e., the observation that the large majority of basal- and squamous-cell cancers arise on the head and neck confirms the importance of long-term ultraviolet exposure; the relative excess of squamous-cell as compared to basal-cell neoplasms on the upper limb may suggest the role of exposure to other (chemical) carcinogens; and the proportional excess of melanomas on the trunk in males and lower limb in females further indicates that intermittent exposure to sunlight is probably the relevant aetiologic factor for melanocytic skin neoplasms.

Improving outcomes for people with skin tumours including melanoma (update)

The management of low-risk basal cell carcinomas in the community.In February 2006, the National Institute for Health and Clinical Excellence (NICE) published service guidance on skin cancer, ‘Improving outcomes for people with skin tumours including melanoma’ (NICE guidance on cancer services). Many of the recommendations in this guidance were converted into peer review measures published in the ‘Manual for cancer services 2008: skin measures..

Molecular analysis of non-melanoma skin cancer

SUMMARY:Cylindroma, trichoepithelioma and spiradenoma are benign tumors of hair follicle. They are caused by mutations and loss of heterozygosity in the CYLD gene. CYLD is a ubiquitously expressed, but the tumors are restricted to skin, suggesting that the tumorigenesis is influenced by skin-specific regulators and probably by mutations in other genes. The objectives of the thesis were to analyze the molecular mechanisms leading to the aforementioned tumors. In the first project, we have identified five new mutations in CYLD gene in tive families affected with different combinations of these skin appendage tumors. F our of these mutations caused the introduction of a premature stop codon in CYLD protein sequence, but one was a missense mutation changing aspartic acid 681 into glycine (D68lG), in patients exhibiting multiple trichoepitheliomas. CYLD is a deubiquitinase which can downregulate NF-κB and INK pathways through the deubiquitination of TRAF2, for example. We showed that the CYLD-D681G mutant was unable to remove polyubiquitin chains from TRAF2. We also proved that CYLD-D68lG could not inhibit TRAP 2- or TNFα- mediated NF-κB or INK activations in 293T cells. These results underlined the importance of the D68l residue for the enzymatic activity of CYLD. TRAP-interacting protein (TRIP), which is a E3-Ubiquitin ligase, is a partner of CYLD. In the second project of the thesis, we studied the function of TRIP in the epidermis. We found that TRIP was a nucleolar protein in cultured human primary keratinocytes (HEK) and HeLa cells, and was detected in the midbody of HeLa cells. Moreover, TRIP expression was shown to be downregulated through a PKC-dependent mechanism before induction of keratinocyte differentiation. We also proved that TRIP was upregulated in basal cell carcinomas. Furthermore, TRIP was found to be important for keratinocyte survival and proliferation through the regulation of the Gl/S transition. Our results suggest that TRIP may be involved in keratinocyte tumorigenesis.RÉSUMÉ :Les cylindromes, trichoépithéliomes et spiradénomes sont des tumeurs bénignes du follicule pileux causées par des mutations et une perte d'hétérozygotie du gène CYLD. CYLD est ubiquitaire mais les tumeurs sont limitées à la peau, suggérant que la tumorigénèse est influencée par des protéines spécifiques de la peau et par des mutations dans d'autres gènes. Les objectifs de la thèse étaient d'2malyser les mécanismes moléculaires aboutissant à la formation de ces tumeurs. Dans le premier projet, cinq nouvelles mutations du gène CYLD ont été identifiées chez cinq familles présentant différentes combinaisons des tumeurs citées ci- dessus. Quatre de ces mutations causaient I' introduction d'un codon stop prématuré dans la séquence protéique, mais une était une mutation «misser1se» changeant l'aspartate 681 en résidu glycine (D68lG) chez des patients présentant des trichoépithéliomes multiples. CYLD est une déubiquitinase qui inhibe les voies de signalisation de NF-κB et JNK, en déubiquitinant notamment TRAF2. Nous avons montré que la protéine mutante CYLD- D68lG ne pouvait pas cliver la chaîne de poly-ubiquitines liée à TRAF2. CYLD-D68lG était aussi incapable d'inhiber l'activation de NF-κB ou de JNK induite par TRAF2 ou TNF-o dans les cellules 293T. Ces résultats ont donc souligné l'impo1tance du résidu D68l pour l'activité de CYLD. «TRAF-interacting protein (TRIP)», qui est une «E3-ubiquitin-ligase», est un partenaire de CYLD. Dans le second proj et de la thèse, nous avons étudié la fonction de TRIP dans l'épidenne. Nous avons montrépque TRIP était nucléolaire dans les cellules HeLa et les kératinocytes primaires humains en culture et était détectée dans le «midbody» des cellules HeLa. Nous avons prouvé que l'ARNm de TRIP était diminué avant l'induction de la différentiation des kératinocytes, par un mécanisme dépendent de la protéine kinase C, tandis qu'il était augmenté dans les carcinomes baso-cellulaires. Nous avons aussi montré que TRIP influençait la prolifération et la survie des kératinocytes en régulant la transition G1/S, Nos résultats suggèrent que TRIP est peut-être impliquée dans la tumorigénèse des kératinocytes. 7

Lack of evidence for KRAS oncogenic mutations in triple-negative breast cancer.

BACKGROUND Mutational analysis of the KRAS gene has recently been established as a complementary in vitro diagnostic tool for the identification of patients with colorectal cancer who will not benefit from anti-epidermal growth factor receptor (EGFR) therapies. Assessment of the mutation status of KRAS might also be of potential relevance in other EGFR-overexpressing tumors, such as those occurring in breast cancer. Although KRAS is mutated in only a minor fraction of breast tumors (5%), about 60% of the basal-like subtype express EGFR and, therefore could be targeted by EGFR inhibitors. We aimed to study the mutation frequency of KRAS in that subtype of breast tumors to provide a molecular basis for the evaluation of anti-EGFR therapies. METHODS Total, genomic DNA was obtained from a group of 35 formalin-fixed paraffin-embedded, triple-negative breast tumor samples. Among these, 77.1% (27/35) were defined as basal-like by immunostaining specific for the established surrogate markers cytokeratin (CK) 5/6 and/or EGFR. KRAS mutational status was determined in the purified DNA samples by Real Time (RT)-PCR using primers specific for the detection of wild-type KRAS or the following seven oncogenic somatic mutations: Gly12Ala, Gly12Asp, Gly12Arg, Gly12Cys, Gly12Ser, Gly12Val and Gly13Asp. RESULTS We found no evidence of KRAS oncogenic mutations in all analyzed tumors. CONCLUSIONS This study indicates that KRAS mutations are very infrequent in triple-negative breast tumors and that EGFR inhibitors may be of potential benefit in the treatment of basal-like breast tumors, which overexpress EGFR in about 60% of all cases.

Pattern of recurrence of early breast cancer is different according to intrinsic subtype and proliferation index.

INTRODUCTION Recurrence risk in breast cancer varies throughout the follow-up time. We examined if these changes are related to the level of expression of the proliferation pathway and intrinsic subtypes. METHODS Expression of estrogen and progesterone receptor, Ki-67, human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR) and cytokeratin 5/6 (CK 5/6) was performed on tissue-microarrays constructed from a large and uniformly managed series of early breast cancer patients (N = 1,249). Subtype definitions by four biomarkers were as follows: luminal A (ER + and/or PR+, HER2-, Ki-67 <14), luminal B (ER + and/or PR+, HER2-, Ki-67 ≥14), HER2-enriched (any ER, any PR, HER2+, any Ki-67), triple-negative (ER-, PR-, HER2-, any Ki-67). Subtype definitions by six biomarkers were as follows: luminal A (ER + and/or PR+, HER2-, Ki-67 <14, any CK 5/6, any EGFR), luminal B (ER + and/or PR+, HER2-, Ki-67 ≥14, any CK 5/6, any EGFR), HER2-enriched (ER-, PR-, HER2+, any Ki-67, any CK 5/6, any EGFR), Luminal-HER2 (ER + and/or PR+, HER2+, any Ki-67, any CK 5/6, any EGFR), Basal-like (ER-, PR-, HER2-, any Ki-67, CK5/6+ and/or EGFR+), triple-negative nonbasal (ER-, PR-, HER2-, any Ki-67, CK 5/6-, EGFR-). Each four- or six-marker defined intrinsic subtype was divided in two groups, with Ki-67 <14% or with Ki-67 ≥14%. Recurrence hazard rate function was determined for each intrinsic subtype as a whole and according to Ki-67 value. RESULTS Luminal A displayed a slow risk increase, reaching its maximum after three years and then remained steady. Luminal B presented most of its relapses during the first five years. HER2-enriched tumors show a peak of recurrence nearly twenty months post-surgery, with a greater risk in Ki-67 ≥14%. However a second peak occurred at 72 months but the risk magnitude was greater in Ki-67 <14%. Triple negative tumors with low proliferation rate display a smooth risk curve, but with Ki-67 ≥14% show sharp peak at nearly 18 months. CONCLUSIONS Each intrinsic subtype has a particular pattern of relapses over time which change depending on the level of activation of the proliferation pathway assessed by Ki-67. These findings could have clinical implications both on adjuvant treatment trial design and on the recommendations concerning the surveillance of patients.

Predicting response and survival in chemotherapy-treated triple-negative breast cancer.

BACKGROUND In this study, we evaluated the ability of gene expression profiles to predict chemotherapy response and survival in triple-negative breast cancer (TNBC). METHODS Gene expression and clinical-pathological data were evaluated in five independent cohorts, including three randomised clinical trials for a total of 1055 patients with TNBC, basal-like disease (BLBC) or both. Previously defined intrinsic molecular subtype and a proliferation signature were determined and tested. Each signature was tested using multivariable logistic regression models (for pCR (pathological complete response)) and Cox models (for survival). Within TNBC, interactions between each signature and the basal-like subtype (vs other subtypes) for predicting either pCR or survival were investigated. RESULTS Within TNBC, all intrinsic subtypes were identified but BLBC predominated (55-81%). Significant associations between genomic signatures and response and survival after chemotherapy were only identified within BLBC and not within TNBC as a whole. In particular, high expression of a previously identified proliferation signature, or low expression of the luminal A signature, was found independently associated with pCR and improved survival following chemotherapy across different cohorts. Significant interaction tests were only obtained between each signature and the BLBC subtype for prediction of chemotherapy response or survival. CONCLUSIONS The proliferation signature predicts response and improved survival after chemotherapy, but only within BLBC. This highlights the clinical implications of TNBC heterogeneity, and suggests that future clinical trials focused on this phenotypic subtype should consider stratifying patients as having BLBC or not.

Transcription factors link mouse WAP-T mammary tumors with human breast cancer.

Mouse models are important tools to decipher the molecular mechanisms of mammary carcinogenesis and to mimic the respective human disease. Despite sharing common phenotypic and genetic features, the proper translation of murine models to human breast cancer remains a challenging task. In a previous study we showed that in the SV40 transgenic WAP-T mice an active Met-pathway and epithelial-mesenchymal characteristics distinguish low- and high-grade mammary carcinoma. To assign these murine tumors to corresponding human tumors we here incorporated the analysis of expression of transcription factor (TF) coding genes and show that thereby a more accurate interspecies translation can be achieved. We describe a novel cross-species translation procedure and demonstrate that expression of unsupervised selected TFs, such as ELF5, HOXA5 and TFCP2L1, can clearly distinguish between the human molecular breast cancer subtypes-or as, for example, expression of TFAP2B between yet unclassified subgroups. By integrating different levels of information like histology, gene set enrichment, expression of differentiation markers and TFs we conclude that tumors in WAP-T mice exhibit similarities to both, human basal-like and non-basal-like subtypes. We furthermore suggest that the low- and high-grade WAP-T tumor phenotypes might arise from distinct cells of tumor origin. Our results underscore the importance of TFs as common cross-species denominators in the regulatory networks underlying mammary carcinogenesis.

Risk of prostate, breast and colorectal cancer after skin cancer diagnosis.

Ultraviolet radiation is the major cause of skin cancer, but promotes vitamin D synthesis, and vitamin D has been inversely related to the risk of several common cancers including prostate, breast and colorectum. We therefore computed the incidence of prostate, breast and colorectal cancer following skin cancer using the datasets of the Swiss cancer Registries of Vaud and Neuchâtel. Between 1974 and 2005, 6,985 histologically confirmed squamous cell skin cancers, 21,046 basal cell carcinomas and 3,346 cutaneous malignant melanomas were registered, and followed up to the end of 2005 for the occurrence of second primary cancer of the prostate, breast and colorectum. Overall, 680 prostate cancers were observed versus 568.3 expected (standardized incidence ratio (SIR) = 1.20; 95% confidence interval (CI): 1.11-1.29), 440 breast cancers were observed versus 371.5 expected (SIR = 1.18; 95% CI: 1.08-1.30) and 535 colorectal cancers were observed versus 464.6 expected (SIR = 1.15; 95% CI: 1.06-1.25). When basal cell, squamous cell and skin melanoma were considered separately, all the SIRs for prostate, breast and colorectal cancers were around or slightly above unity. Likewise, the results were consistent across strata of age at skin cancer diagnosis and location (head and neck versus others), and for male and female colorectal cancers. These findings, based on a population with a long tradition of systematic histologic examination of all surgically treated skin lesions, do not support the hypothesis that prostate, breast and colorectal cancer risk is decreased following skin cancer.

The TRAF-interacting protein (TRIP) is a regulator of keratinocyte proliferation.

The TRAF-interacting protein (TRIP/TRAIP) is a RING-type E3 ubiquitin ligase inhibiting tumor necrosis factor-α (TNF-α)-mediated NF-κB activation. TRIP ablation results in early embryonic lethality in mice. To investigate TRIP function in epidermis, we examined its expression and the effect of TRIP knockdown (KD) in keratinocytes. TRIP mRNA expression was strongly downregulated in primary human keratinocytes undergoing differentiation triggered by high cell density or high calcium. Short-term phorbol-12-myristate-13-acetate (TPA) treatment or inhibition of phosphatidylinositol-3 kinase signaling in proliferative keratinocytes suppressed TRIP transcription. Inhibition by TPA was protein kinase C dependent. Keratinocytes undergoing KD of TRIP expression by lentiviral short-hairpin RNA (shRNA; T4 and T5) had strongly reduced proliferation rates compared with control shRNA. Cell cycle analysis demonstrated that TRIP-KD caused growth arrest in the G1/S phase. Keratinocytes with TRIP-KD resembled differentiated cells consistent with the augmented expression of differentiation markers keratin 1 and filaggrin. Luciferase-based reporter assays showed no increase in NF-κB activity in TRIP-KD keratinocytes, indicating that NF-κB activity in keratinocytes is not regulated by TRIP. TRIP expression was increased by ∼2-fold in basal cell carcinomas compared with normal skin. These results underline the important role of TRIP in the regulation of cell cycle progression and the tight linkage of its expression to keratinocyte proliferation.

Meta-analysis of gene expression profiles in breast cancer: toward a unified understanding of breast cancer subtyping and prognosis signatures.

INTRODUCTION: Breast cancer subtyping and prognosis have been studied extensively by gene expression profiling, resulting in disparate signatures with little overlap in their constituent genes. Although a previous study demonstrated a prognostic concordance among gene expression signatures, it was limited to only one dataset and did not fully elucidate how the different genes were related to one another nor did it examine the contribution of well-known biological processes of breast cancer tumorigenesis to their prognostic performance. METHOD: To address the above issues and to further validate these initial findings, we performed the largest meta-analysis of publicly available breast cancer gene expression and clinical data, which are comprised of 2,833 breast tumors. Gene coexpression modules of three key biological processes in breast cancer (namely, proliferation, estrogen receptor [ER], and HER2 signaling) were used to dissect the role of constituent genes of nine prognostic signatures. RESULTS: Using a meta-analytical approach, we consolidated the signatures associated with ER signaling, ERBB2 amplification, and proliferation. Previously published expression-based nomenclature of breast cancer 'intrinsic' subtypes can be mapped to the three modules, namely, the ER-/HER2- (basal-like), the HER2+ (HER2-like), and the low- and high-proliferation ER+/HER2- subtypes (luminal A and B). We showed that all nine prognostic signatures exhibited a similar prognostic performance in the entire dataset. Their prognostic abilities are due mostly to the detection of proliferation activity. Although ER- status (basal-like) and ERBB2+ expression status correspond to bad outcome, they seem to act through elevated expression of proliferation genes and thus contain only indirect information about prognosis. Clinical variables measuring the extent of tumor progression, such as tumor size and nodal status, still add independent prognostic information to proliferation genes. CONCLUSION: This meta-analysis unifies various results of previous gene expression studies in breast cancer. It reveals connections between traditional prognostic factors, expression-based subtyping, and prognostic signatures, highlighting the important role of proliferation in breast cancer prognosis.

Identification of molecular subtypes and gene expression patterns of breast cancer analysing RNA-seq data

Breast cancer is the most common diagnosed cancer and the leading cause of cancer death among females worldwide. It is considered a highly heterogeneous disease and it must be classified into more homogeneous groups. Hence, the purpose of this study was to classify breast tumors based on variations in gene expression patterns derived from RNA sequencing by using different class discovery methods. 42 breast tumors paired-samples were sequenced by Illumine Genome Analyzer and the data was analyzed and prepared by TopHat2 and htseq-count. As reported previously, breast cancer could be grouped into five main groups known as basal epithelial-like group, HER2 group, normal breast-like group and two Luminal groups with a distinctive expression profile. Classifying breast tumor samples by using PAM50 method, the most common subtype was Luminal B and was significantly associated with ESR1 and ERBB2 high expression. Luminal A subtype had ESR1 and SLC39A6 significant high expression, whereas HER2 subtype had a high expression of ERBB2 and CNNE1 genes and low luminal epithelial gene expression. Basal-like and normal-like subtypes were associated with low expression of ESR1, PgR and HER2, and had significant high expression of cytokeratins 5 and 17. Our results were similar compared with TGCA breast cancer data results and with known studies related with breast cancer classification. Classifying breast tumors could add significant prognostic and predictive information to standard parameters, and moreover, identify marker genes for each subtype to find a better therapy for patients with breast cancer.

Plastic surgery in chest wall reconstruction: relevant aspects - case series

Objective: to discuss the participation of Plastic Surgery in the reconstruction of the chest wall, highlighting relevant aspects of interdisciplinaryness. Methods: we analyzed charts from 20 patients who underwent extensive resection of the thoracic integument, between 2000 and 2014, recording the indication of resection, the extent and depth of the raw areas, types of reconstructions performed and complications. Results: among the 20 patients, averaging 55 years old, five were males and 15 females. They resections were: one squamous cell carcinoma, two basal cell carcinomas, five chondrosarcomas and 12 breast tumors. The extent of the bloody areas ranged from 4x9 cm to 25x40 cm. In 12 patients the resection included the muscular plane. In the remaining eight, the tumor removal achieved a total wall thickness. For reconstruction we used: one muscular flap associated with skin grafting, nine flaps and ten regional fasciocutaneous flaps. Two patients undergoing reconstruction with fasciocutaneous flaps had partially suffering of the flap, solved with employment of a myocutaneous flap. The other patients displayed no complications with the techniques used, requiring only one surgery. Conclusion: the proper assessment of local tissues and flaps available for reconstruction, in addition to the successful integration of Plastic Surgery with the specialties involved in the treatment, enable extensive resections of the chest wall and reconstructions that provide patient recovery.