Studio di marcatori biologici prognostici nel linfoma di Hodgkin

Recent reports showed that early-interim PET-scan is the only tool predicting treatment outcome in advanced-stage classical Hodgkin lymphoma (asCHL). We evaluated the prognostic impact of a series of immunohistochemical markers, mentioned in literature as prognostic factors, on tissue microarrays assembled from biopsies of 220 patients: STAT1, SAP, TOP2A, PCNA and CD20, both in neoplastic (HRSC) and microenvironment cells (MC); RRM2, MAD2, CDC2, BCL2, P53, BCL11A and EBER in HRSC; ALDH1A1, TIA-1, granzyme B, perforin, FOXP3, and PD-1 in MC. All patients had been treated with standard ABVD ± Rx therapy. Interim-PET after 2 ABVD courses was evaluated according to the criteria indicated by Gallamini in his study (Journal of Clinical Oncology, 2007). The survival analysis has been performed in a subset of 138 patients whose complete clinical information were available: the mean age was 33.3 years (14-79), the stage III-IVB in 98 and IIB in 40, and the mean follow-up 38.1 months (7.6-71.9). Histopathology review showed: NS-I 75, NS-II 22, MC 20, DL 3, and CHL/nos 18 cases. Interim-PET was positive in 30 patients, while treatment failure was recorded in 32. In univariate analysis the factors related to treatment outcome were BCL2 on HRSC (cut-off value 50%), STAT1/SAP on MC, and PET (Log-rank 6.9, 7.9 and 93.9 respectively). The combined expression of STAT1 and SAP was scored in three levels depending on the architectural pattern: score 0 for expression of both with a diffuse/rosetting pattern; score 1 for discordant combination of diffuse/rosetting and scattered patterns; score 2 for both markers with a scattered pattern; the 3y-PFS were 87.4%, 69.9% and 61.9% respectively. In multivariate analysis PET, BCL2 and STAT1/SAP remained significant (HR: 24.8, 4.6, 7.5 and 5.6, respectively; p<.01). The proposed model is able to predict treatment response in AsCHL, even if with a lower efficacy than PET. However, unlike PET, it can be applied upfront therapy.

Congenital Nystagmus eye movements analysis and oculomotor system models evaluation

The term Congenital Nystagmus (Early Onset Nystagmus or Infantile Nystagmus Syndrome) refers to a pathology characterised by an involuntary movement of the eyes, which often seriously reduces a subject’s vision. Congenital Nystagmus (CN) is a specific kind of nystagmus within the wider classification of infantile nystagmus, which can be best recognized and classified by means of a combination of clinical investigations and motility analysis; in some cases, eye movement recording and analysis are indispensable for diagnosis. However, interpretation of eye movement recordings still lacks of complete reliability; hence new analysis techniques and precise identification of concise parameters directly related to visual acuity are necessary to further support physicians’ decisions. To this aim, an index computed from eye movement recordings and related to the visual acuity of a subject is proposed in this thesis. This estimator is based on two parameters: the time spent by a subject effectively viewing a target (foveation time - Tf) and the standard deviation of eye position (SDp). Moreover, since previous studies have shown that visual acuity largely depends on SDp, a data collection pilot study was also conducted with the purpose of specifically identifying eventual slow rhythmic component in the eye position and to characterise in more detail the SDp. The results are presented in this thesis. In addition, some oculomotor system models are reviewed and a new approach to those models, i.e. the recovery of periodic orbits of the oculomotor system in patients with CN, is tested on real patients data. In conclusion, the results obtained within this research consent to completely and reliably characterise the slow rhythmic component sometimes present in eye position recordings of CN subjects and to better classify the different kinds of CN waveforms. Those findings can successfully support the clinicians in therapy planning and treatment outcome evaluation.

Mechanisms Contributing to Tyrosin Kinase Inhibitor Resistance in GISTs: Toward a Personalized Therapy

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract. This work considers the pharmacological response in GIST patients treated with imatinib by two different angles: the genetic and somatic point of view. We analyzed polymorphisms influence on treatment outcome, keeping in consideration SNPs in genes involved in drug transport and folate pathway. Naturally, all these intriguing results cannot be considered as the only main mechanism in imatinib response. GIST mainly depends by oncogenic gain of function mutations in tyrosin kinase receptor genes, KIT or PDGFRA, and the mutational status of these two genes or acquisition of secondary mutation is considered the main player in GIST development and progression. To this purpose we analyzed the secondary mutations to better understand how these are involved in imatinib resistance. In our analysis we considered both imatinib and the second line treatment, sunitinib, in a subset of progressive patients. KIT/PDGFRA mutation analysis is an important tool for physicians, as specific mutations may guide therapeutic choices. Currently, the only adaptations in treatment strategy include imatinib starting dose of 800 mg/daily in KIT exon-9-mutated GISTs. In the attempt to individualize treatment, genetic polymorphisms represent a novelty in the definition of biomarkers of imatinib response in addition to the use of tumor genotype. Accumulating data indicate a contributing role of pharmacokinetics in imatinib efficacy, as well as initial response, time to progression and acquired resistance. At the same time it is becoming evident that genetic host factors may contribute to the observed pharmacokinetic inter-patient variability. Genetic polymorphisms in transporters and metabolism may affect the activity or stability of the encoded enzymes. Thus, integrating pharmacogenetic data of imatinib transporters and metabolizing genes, whose interplay has yet to be fully unraveled, has the potential to provide further insight into imatinib response/resistance mechanisms.

Treatment of knee articular cartilage defects: surgical strategies, results and analysis of factors determining the clinical outcome

Articular cartilage lesions, with their inherent limited healing potential, are hard to treat and remain a challenging problem for orthopedic surgeons. Despite the development of several treatment strategies, the real potential of each procedure in terms of clinical benefit and effects on the joint degeneration processes is not clear. Aim of this PhD project was to evaluate the results, both in terms of clinical and imaging improvement, of new promising procedures developed to address the challenging cartilage pathology. Several studies have been followed in parallel and completed over the 3-year PhD, and are reported in detail in the following pages. In particular, the studies have been focused on the evaluation of the treatment indications of a scaffold based autologous chondrocyte implantation procedure, documenting its results for the classic indication of focal traumatic lesions, as well as its use for the treatment of more challenging patients, older, with degenerative lesions, or even as salvage procedure for more advanced stages of articular degeneration. The second field of study involved the analysis of the results obtained treating lesions of the articular surface with a new biomimetic osteochondral scaffold, which showed promise for the treatment of defects where the entire osteochondral unit is involved. Finally, a new minimally invasive procedure based on the use of growth factors derived from autologous platelets has been explored, showing results and underlining indicatios for the treatment of cartilage lesions and different stages of joint degeneration. These studies shed some light on the potential of the evaluated procedures, underlining good results as well as limits, they give some indications on the most appropriate candidates for their application, and document the current knowledge on cartilage treatment procedures suggesting the limitations that need to be addressed by future studies to improve the management of cartilage lesions.