Response by Choi criteria to sunitinib plus octreotide LAR in a functional heavily pretreated advanced pancreatic neuroendocrine tumor.

Pancreatic neuroendocrine tumors (PNETs) are rare malignancies that arise from the islets of Langerhans. The role of standard chemotherapy in advanced well-differentiated PNETs remains to be defined. Sunitinib is an oral multitargeted inhibitor with antiangiogenic and antitumor properties that has shown significant improvement in survival in metastatic PNETs, although objective responses by Response Evaluation Criteria in Solid Tumors were only 9%. We herein report on the case of a middle-aged woman with metastatic PNET who was heavily pretreated for her advanced disease with limited success, and who showed clinical, biochemical, and radiological responses by using Choi criteria but not Response Evaluation Criteria in Solid Tumors criteria. To our knowledge, this is the first reported case of treatment with sunitinib in a patient with PNET in response to Choi criteria.

Multidisciplinary management in rectal cancer.

The treatment of rectal cancer has evolved over the last few decades from surgery alone to treatments with trimodal therapy for high-risk patients. The involvement of a multidisciplinary team of radiologists, pathologists, surgeons, radiotherapists and medical oncologists is now fundamental for decision-making and outcomes. The evolution of different diagnostic and therapeutic techniques has optimised the therapeutic rate. Future studies will determine the optimal regimen for inducing complete responses in locally advanced disease and whether the intensification of local treatments could enable the use of more conservative treatments, as for other tumour locations. The study of biomarkers will be essential in this respect.

Influence of thymidylate synthase DNA polymorphisms and gender on the clinical evolution of patients with advanced colorectal cancer.

Experimental evidence has revealed that several thymidylate synthase (TS) DNA polymorphisms modulate gene expression, which, in turn is known to be down-regulated by oestrogen receptor subtypes. Consequently, this process might be influenced by female hormones. Based on these data, we investigated whether patient's gender and TS polymorphism exert an interactive effect on the clinical evolution of patients with advanced colorectal cancer (CRC) subjected to 5 fluorouracil (5FU)-based adjuvant chemotherapy. A retrospective study was carried out on paraffin-embedded sections from 81 CRC patients. A variable tandem repeat (VNTR) of 28 bp, a G/C single nucleotide polymorphism (SNP), and a deletion of 6 bp (ins1494del 6 bp) were studied. Genotyping methods were polymerase chain reaction (PCR) for VNTR, and PCR followed by restriction length fragment polymorphism (PCR-RFLP) for SNP and ins1494del 6 bp. The effect of TS genotype and gender on overall and progression-free survival was assessed in univariate and multivariate (Cox regression model) tests. In male patients, the study of combined TS genotypes showed that G&6+/6+ was an adverse marker for overall (P=0.04; median: not reached) and progression-free survival (P=0.03; median: 12 months, 95% CI: 0-32.4). In the multivariate analysis, the concurrence of G&6+/6+ combination and male patients resulted in a 5.5-fold increased risk of relapse or disease progression (95% CI: 1-32.1; likelihood test P=0.004; interaction P=0.06). TS genotype did not affect survival among women. The present study supports that the effect of TS polymorphisms on the clinical evolution of advanced CRC patients is significantly influenced by gender.

Combination of polymorphisms within 5' and 3' untranslated regions of thymidylate synthase gene modulates survival in 5 fluorouracil-treated colorectal cancer patients.

In the present study we explored the effect of three polymorphisms of the TS gene on overall and progression- free survival of colorectal cancer (CRC) patients subjected to 5FU chemotherapy. A 28 bp variable number of tandem repeats (VNTR), a G/C single nucleotide polymorphism (SNP), and a deletion of 6 bp at position 1494 were studied. The possible combined effect of these DNA polymorphisms on the clinical outcome of patients was also evaluated. A retrospective study was carried out on paraffin-embedded sections from 113 patients diagnosed of advanced CRC. TS genotyping methods were polymerase chain reaction (PCR) for VNTR and PCR, followed by restriction length fragment polymorphism (PCR-RFLP) for SNP and ins/del 6 bp. To study the combined effect of TS polymorphisms, four categories were defined accordingly to the level of expression attributed to SNP and ins/del 6 bp genotypes: C&allele 6-, C&6+/6+, G&allele6- and G&6+/6+. VNTR and ins/del 6 bp genotypes varied with tumour anatomical site: 2R/2R genotype was rare in left-sided tumours (7.0% vs. 26.3% of right-sided and 24.1% of rectal cancers; P<0.01), where the variant allele 6- was very frequent (69.0%). Instead, most patients with right-sided tumours were wild-type homozygous 6+/6+ (63.9%) (P<0.01). Heterozygous 6+/6- genotype was more frequent among tumours classified as C (50.0%) and D (76.5%) Dukes stages (P=0.05). None of the studied polymorphisms alone affected overall or progression-free survival (PFS). C&6+/6+ and G&6+/6+ combined genotypes were respectively associated to the best and worst PFS (P=0.03 when compared with each other), while combinations carrying the allele 6- determined an intermediate evolution that might be indicative of a variable response to chemotherapy. The rate of Dukes B stage tumours was unexpectedly high (59.1%) among patients with the unfavourable G&6+/6+ combination. In our study the combination of high TS expression genotypes G&6+/6+ identifies a group of high risk within CRC patients treated with 5FU.

Thymidylate synthase expression pattern, expression level and single nucleotide polymorphism are predictors for disease-free survival in patients of colorectal cancer treated with 5-fluorouracil.

Several variables associated to thymidylate synthase (TS), the biological target of 5-fluorouracil (5FU) have been studied for their possible role as predictors of the clinical outcome and response to chemotherapy in colorectal cancer (CRC) patients. The level of protein expression and the number of variable tandem-repeats of a 28-bp sequence within the gene promoter have been proposed as predictive and/or prognostic factors with variable agreement, while consensus seems to be achieved with respect to the value of a single nucleotide polymorphism (SNP) described within this same region. More recently, an association between TS expression pattern and survival has been disclosed. Paraffin-embedded sections from 140 CRC patients were analyzed by immuno-histochemistry (Mab TS106) for TS levels and expression pattern. Also, VNTR and SNP were determined by polymerase-chain reaction (PCR) and restriction-length-fragment polymorphism (RFLP) in 123 and 112 patients, respectively. Cytoplasmic expression pattern tended to be associated to C SNP (p=0.06). Low TS expression levels, cytoplasmic expression pattern and C SNP arose as variables associated to longer progression-free survival (PFS) in patients treated with 5FU. Accordingly, patients having at least two favourable or unfavourable variables were classified respectively as 'low risk' and 'high risk', the former showing significantly longer PFS (p=0.0299). The possibility for designing a selection method for subsequent therapies is suggested on the basis of a probable combined effect of the above mentioned parameters but further studies in larger populations are needed to confirm these results.

Thymidylate synthase expression pattern is a prognostic factor in patients of colorectal cancer treated with 5-fluorouracil.

High intratumoral expression of thymidylate synthase (TS) has been reported as a factor of poor prognosis in patients with advanced colorectal cancer (CRC), but such association is unclear in some studies. Also, TS has been stated as a typical cytosolic enzyme, but nuclear location has been occasionally reported, and data on the clinical meaning of TS intracellular location are scarce. A retrospective study was performed in paraffin-embedded sections of primary tumor from 77 CRC patients treated with surgical resection and adjuvant 5-FU-based chemotherapy. TS levels and expression patterns were determined by immunohistochemistry (IHQ) using TS-106 antibody. Qualitative and quantitative variables were compared respectively by chi2 and Kruskal-Wallis tests; overall survival (OS) and disease-free survival (DFS) were analyzed with the Kaplan-Meier method and compared using the log-rank and Wilcoxon tests. TS was cytoplasmic in 27.1% of positive tumors and both, nuclear and cytoplasmic in 72.9%; specimens from seven patients (9.1%) lacked TS expression. TS levels were high in 21.6% of tumors with nuclear expression and low in 5.6%, whereas 68.4% of cytoplasmic ones showed low immunostaining intensity (p=0.02); cytoplasmic pattern was also associated to longer OS (p<0.009) and DFS (p=0.003). In patients with nuclear expression, low TS expression was associated to shorter OS (p<0.003) and DFS (p<0.04). These results indicate that, in our study, TS immunostaining patterns were related with OS and DFS, the best prognostic corresponding to cytoplasmic one, and, within the subset of patients with nuclear expression, low TS levels were associated to worse clinical outcome.