Clinicopathological profile of lung cancer at a tertiary care center.

BACKGROUND: Lung cancer is one of the most common malignancies with high morbidity and mortality. Nonsmall cell lung cancer (NSCLC) accounts for majority of cases. AIMS: This study aims to study the clinical and pathological features of lung cancer patients treated at our institute between January 2011 and December 2016. SUBJECTS AND METHODS: It is a retrospective study. 446 patients of lung cancer were retrospectively analyzed for demographic data, history of smoking, histological type, and presence of epidermal growth factor receptor (EGFR) mutation/anaplastic lymphoma kinase (ALK) mutations. RESULTS: Of the 446 patients analyzed, 304 (68%) were males and 142 (32%) were females, with the ratio being 2:1. Most of our patients had a lesion localizing to the right side (45.7%) than left (37.8%). NSCLC was reported in 81.1% of our patients. EGFR mutation was found in 60 (24%) patients, the most common mutation being the deletion of exon 19 (73%) followed by L858R mutation (21.6%). CONCLUSIONS: EGFR and ALK mutation testing of all the lung cancer patients is to be encouraged as these mutations form druggable targets.

Evidence for presence of mismatch repair gene expression positive Lynch syndrome cases in India.

Lynch syndrome (LS), the most common form of familial CRC predisposition that causes tumor onset at a young age, is characterized by the presence of microsatellite instability (MSI) in tumors due to germline inactivation of mismatch repair (MMR) system. Two MMR genes namely MLH1 and MSH2 account for majority of LS cases while MSH6 and PMS2 may account for a minor proportion. In order to identify MMR genes causing LS in India, we analyzed MSI and determined expression status of the four MMR genes in forty eight suspected LS patient colorectal tumor samples. Though a majority exhibited MSI, only 58% exhibited loss of MMR expression, a significantly low proportion compared to reports from other populations. PCR-DNA sequencing and MLPA-based mutation and exonic deletion/duplication screening respectively, revealed genetic lesions in samples with and without MMR gene expression. Interestingly, tumor samples with and without MMR expression exhibited significant differences with respect to histological (mucin content) and molecular (instability exhibited by mononucleotide microsatellites) features. The study has revealed for the first time a significant proportion of LS tumors not exhibiting loss of MMR expression.

Evidence for possible non-canonical pathway(s) driven early-onset colorectal cancer in India.

Two genetic instability pathways viz. chromosomal instability, driven primarily by APC mutation induced deregulated Wnt signaling, and microsatellite instability (MSI) caused by mismatch repair (MMR) inactivation, together account for >90% of late-onset colorectal cancer (CRC). Our understanding of early-onset sporadic CRC is however comparatively limited. In addition, most seminal studies have been performed in the western population and analyses of tumorigenesis pathway(s) causing CRC in developing nations have been rare. We performed a comparative analysis of early and late-onset CRC from India with respect to common genetic aberrations including Wnt, KRAS, and p53 (constituting the classical CRC progression sequence) in addition to MSI. Our results revealed the absence of Wnt and MSI in a significant proportion of early-onset as against late-onset CRC in India. In addition, KRAS mutation frequency was significantly lower in early-onset CRC indicating that a significant proportion of CRC in India may follow tumorigenesis pathways distinct from the classical CRC progression sequence. Our study has therefore revealed the possible existence of non-canonical tumorigenesis pathways in early-onset CRC in India.

Metastatic squamous cell carcinoma thyroid from functionally cured cancer cervix.

The authors report a very unusual occurrence of a metastatic squamous carcinoma to thyroid gland from a treated squamous cell carcinoma cervix 12 years before with no recurrence at the primary site. The case also has an additional complexity of rapid progression of the metastatic thyroid carcinoma to wide spread dissemination to lungs and bones while on concurrent chemo radio therapy confirming the aggressiveness of the entity.

F18 FDG positron emission tomography revelation of primary testicular lymphoma with concurrent multiple extra nodal involvement.

Primary testicular lymphoma (PTL) a relatively rare disease of non-Hodgkin's lymphomas occurring with a lesser incidence of 1-2% has a propensity to occur at later ages above 50 years. PTL spreads to extra nodal sites due to deficiency of extra cellular adhesion molecules. We present detection of multiple sites of extra nodal involvement of PTL by F-18 positron emission tomography/computed tomography study aiding early detection of the dissemination thus aiding in staging and management.

PNUTS functions as a proto-oncogene by sequestering PTEN.

PTEN is a well-defined tumor suppressor gene that antagonizes the PI3K/Akt pathway to regulate a multitude of cellular processes, such as survival, growth, motility, invasiveness, and angiogenesis. While the functions of PTEN have been studied extensively, the regulation of its activity during normal and disease conditions still remains incompletely understood. In this study, we identified the protein phosphatase-1 nuclear targeting subunit PNUTS (PPP1R10) as a PTEN-associated protein. PNUTS directly interacted with the lipid-binding domain (C2 domain) of PTEN and sequestered it in the nucleus. Depletion of PNUTS leads to increased apoptosis and reduced cellular proliferation in a PTEN-dependent manner. PNUTS expression was elevated in certain cancers compared with matched normal tissues. Collectively, our studies reveal PNUTS as a novel PTEN regulator and a likely oncogene.

Thymidylate synthase gene polymorphisms effecting 5-FU response in breast cancer patients.

Our study supports the Drug-Gene Interaction principle, where patients experience adverse drug reactions (ADRs) due to genetic predisposition or due to single nucleotide polymorphisms (SNPs) in drug metabolizing genes. The target enzyme for 5- Fluorouracil is thymidylate synthase (TYMS) this enzyme is also involved in folate metabolism. We determined the frequencies of polymorphisms in drug metabolizing enzyme like TYMS and correlated the drug response in 140 breast cancer patients compared to 150 controls, using PCR and RFLP method. In our results the TYMS1494del polymorphism was statistically significant; allele frequencies for 6bp deletion and 6bp insertion were 0.85 and 0.15 in BC (Breast Cancer) patients compared with 0.95 and 0.04 in controls. The enhancer region 2R/3R heterozygote genotypes were found to be not significant for BC risk. In this study combined genotypes showed 2 fold increased risk of BC. Frequency distribution of 2R and 3R allele among BC patients was 0.85 and 0.15 and 0.95 and 0.04 in controls respectively. Correlation analysis of TYMS enhancer region polymorphisms with drug response suggested that the response was poor in BC patients with 2R/3R and 2R/2R genotypes, but patients with poor response were fewer in number, that this gene may be important in drug response. Genetic screening of the drug metabolizing enzyme like TYMS for the presence of polymorphisms in breast cancer patients will become increasingly useful in individualizing drug therapy.

Undifferentiated sarcoma of the mitral valve with secondaries in brain in a girl of 22 years.

During a mitral valve replacement surgery in a girl of 22 years of age, it was accidentally discovered that the valve was destroyed due to a tumor and the histopathology and immunohistochemistry findings have proved it to be undifferentiated sarcoma. She was advised by the surgeon to go for chemotherapy. There was a delay of three months from the side of the patient to reach us and during that interval she has developed secondaries in the brain. This case is being presented here for its rarity.