Genetic variability & chemotoxicity of 5-fluorouracil & cisplatin in head & neck cancer patients: a preliminary study.

Background & objectives: The efficacy and toxicity of a given chemotherapy regimen varies widely among patients due to the inherited variability of genes that are involved in drug metabolism. There are several crucial enzymes identified involving metabolism of 5-fluorouracil (5-FU) and cisplatin, which are polymorphic. We studied head and neck cancer patients (n=23) on 5-FU and cisplatin combination therapy attending a tertiary care cancer research institute in Gujarat, India, to understand the effect of a particular genotype on toxicity. Methods: The patients were genotyped for dihydropyrimidine (DPYD) (85T>C, IVS14+1G>A, 2846A>T, 2194G>A), thymidylate synthase (TYMS) [28bp tandem repeat in the promoter enhancer region (TSER)], methylenetetrahydrofolate reductase (MTHFR) (677C>T, 1298A>C), glutathione S-transferase P1(GSTP1) (Ile105Val), glutathione S-transferase T1 (GSTT1) (null allele) and glutathione S-transferase M1 (GSTM1) (null allele) by multiplex allele-specific PCR and long range PCR. Results: Of the 23 (19 males 4 females, age range 18-16 yr) patients, two had grade 3 and 4 toxicity while the remaining 21 had 0 to 2 grade toxicity after treatment with 5-FU and cisplatin combination therapy. An association between the genotype of GSTM1 (+/- and -/-) and the toxicity of cisplatin (P=0.043) was observed. Interpretation & conclusions: The findings of this preliminary study suggested an association between the variants of GSTM1 and toxicity observed due to cisplatin. Well planned studies on a large sample of head and neck cancer patients need to be conducted to understand the effects of these genetic variants on toxicity and efficacy of anticancer drugs.

Trisomy 8 in leukemia: A GCRI experience.

Trisomy of chromosome 8 is frequently reported in myeloid lineage disorders and also detected in lymphoid neoplasms as well as solid tumors suggesting its role in neoplastic progression in general. It is likely to be a disease-modulating secondary event with underlying cryptic aberrations as it has been frequently reported in addition to known abnormalities contributing to clinical heterogeneity and modifying prognosis. Here, we share our findings of trisomy 8 in leukemia patients referred for diagnostic and prognostic cytogenetic assessment. Total 60 cases of trisomy 8, as a sole anomaly or in addition to other chromosomal aberrations, were reported (January 2005–September 2008). Unstimulated bone marrow or blood samples were cultured, followed by GTG banding and karyotyping as per the ISCN 2005. Patients with +8 were chronic myeloid leukemia (CML) (36), acute myeloid leukemia (AML) (17), and acute lymphoblastic leukemia (ALL) (7). In 7 patients, trisomy 8 was the sole anomaly, whereas in 6 patients +8 was in addition to normal clone, in 47 patients, the +8 was in addition to t(9;22), t(15;17), and others, including 3 with tetrasomy 8. Only one patient showed constitutional +8. The present study will form the basis of further cumulative studies to correlate potential differential effects of various karyotypic anomalies on disease progression and survival following a therapeutic regime. To unravel the role of extra 8 chromosome, constitutional chromosomal analysis and uniparental disomy will be considered.

Transforming growth factor 2: A predictive marker for breast cancer.

Dual role of TGF- signaling in breast tumorigenesis as an inhibitor in early stages and promoter in advanced stages has been well established and known as TGF- switch. However, the biological mechanisms needs to be explored. Aim of the present study was to look for the usefulness of TGF-2 as a predictive marker for breast cancer and to offer a better predictability to identify patients likely to benefit from antiTGF- strategies. Circulatory as well as transcript levels of TGF-2 were estimated from 118 pretherapeutic breast cancer patients using ELISA and q-PCR with ddCt method. Multifactorial analysis was performed to correlate the results to clinico-pathological prognosticators and Kaplan-Meier survival analysis with a median follow-up of 49 months was also evaluated. Circulating TGF-2 was similar in control and breast cancer patients. TGF-2 was significantly upregulated in advanced tumors compared to early tumors. An inverse correlation was observed between TGF-2 protein and mRNA; nevertheless both exhibited significant correlations with clinico-pathological prognosticators. Higher expression of TGF-2 mRNA was connected to an early relapse in advanced stage than early stage patients. It is the first report to evaluate circulatory and transcript levels exhibiting TGF- switch and confirming the utility of TGF-2 as an important predictive marker for breast cancer.

Fine needle aspiration cytology of anterior mediastinal masses.

OBJECTIVE: The main aim of the study is to evaluate the computed tomography (CT)-guided fine needle aspiration cytology (FNAC) of anterior mediastinal mass as a diagnostic procedure. MATERIALS AND METHODS: In all 135 cases, the material was obtained by CT-guided FNAC technique followed by staining with Papanicolaou and May-Grunwald-Giemsa stains. The histological material was obtained by needle biopsies, wedge biopsies and resection specimens. Immunohistochemical stains were used to confirm diagnosis in selected cases. RESULTS: Among 135 cases, cytohistology correlation was found in 92 cases. Correct typing was done in 53.33% cases. No correlation was found in 14.81% cases. Material was unsatisfactory in 18.51% cases. The diagnostic accuracy and positive predictive values were 85.71% and 78.26%, respectively. CONCLUSION: Although there are some limitations, most lesions of the anterior mediastinum can be diagnosed on FNAC.

Utility of urinary biomarkers in oral cancer.

OBJECTIVE: Oral cancer is the leading malignancy in India, with tobacco playing a major role in the etiology. The aim of the present study was to quantify nitrate+nitrite (NO2+NO3) in tobacco products as well as to study tobacco exposure related biomarkers in controls, patients with oral precancers (OPC) and oral cancer patients. MATERIALS & METHODS: Healthy individuals (n=90) were grouped into without habit of tobacco (NHT, n=30) and healthy individuals with habit of tobacco (WHT, n=60). Oral cancer patients with a tobacco habit were classified into abstinence (n=62) and non-abstinence (n=64) groups according to status at the study time. Urinary nicotine and cotinine levels were analyzed by modified high-pressure liquid chromatography (HPLC) using a UV detector. Levels of NO2+NO3 in tobacco and urine, and urinary thioether levels were estimated by spectrophotometry. RESULTS: NO2+NO3 levels in different types of tobacco product ranged between 0.13 to 3.39 mg/g. The Odds Ratio (OR) analysis indicated positive associations of both smoking and chewing habits of tobacco with high risk of development of oral cancer. Urinary nicotine, cotinine and NO2+NO3 levels were significantly elevated in WHT, patients with OPC and oral cancer patients as compared with the NHT group. This was also the case for urinary thioether levels. Levels of urinary nicotine and cotinine were also higher in the non-abstinence group with oral cancers. CONCLUSION: The results confirmed that tobacco chewing and smoking habits are prominent risk factors for development of oral cancer in the western part of India (Gujarat). Urinary nicotine, cotinine, NO2+NO3 and thioether levels can be helpful for screening programs for oral cancer.

Loss of sex chromosome in acute myeloid leukemia.

Loss of sex chromosomes has been reported in normal and malignant marrows and its frequency increases with age in both situations. It is not clear whether the sex chromosome loss is a critical mutational event for neoplastic transformation or a genetic change related to ageing. The present study was undertaken to analyze incidence of loss of sex chromosomes in leukemia patients. Karyotypic analysis in bone marrow cells was carried out in total 270 AML patients registered at G.C.& R.I. during January 2000 to October 2003. Out of 270, 22 patients had loss of sex chromosome in addition to other disease specific chromosomal abnormalities. Out of 22 patients, 50% (11 of 22) were of the pediatric age (up to 14 years), and only 10% (3 of 22) patients were above the age of 50 years, maximum age being 65 years. On follow-up, only in patients with pathological remission normal 46XX/XY karyotypes were seen. Whereas in patients with persistent leukemic activity, clones with loss of sex chromosome were observed. The results indicate that sex chromosome loss in these cases may be equivalent of a clonal cytogenetic process rather than related to ageing process.