Genetic Testing Is Aiding In Early Detection and Precision Care Of Lung Cancer

Lung cancer accounts for approximately 25% of all cancer-related deaths in the country. Genetic abnormalities can transform normal cells into cancerous ones. Hence, preventive anticancer treatment is crucial, particularly for individuals with a family history of such disease. 

Mumbai's Kokilaben Dhirubhai Ambani Hospital has introduced a new tool- PanPredict Lung Cancer – to facilitate the early identification of cell mutations. The PanPredict Lung Cancer module at the hospital assesses 11 predictive genes, examining both mutations and fusions (167 variants) that serve as important markers for advanced lung cancer patients.

Dr. Amrit Kaur Kaler, a Consultant in Molecular Pathology, emphasized the significance of hereditary cancer testing in estimating an individual's lifetime risk by identifying specific genetic changes. Genetic mutations contribute to an increased risk of developing various types of cancer, although only 5% to 10% of cancers are hereditary. Individuals with a family history of cancer can undergo testing for hereditary genetic variations. This can enhance patient care through early detection, management, prognosis, risk reduction, targeted therapy utilization, and understanding of the implications for other family members. The cost of the Lung Cancer Panel test is Rs 30,000.

The hospital employs a CE-IVD-certified real-time PCR assay that screens for 167 hotspot mutations or fusions of 11 genes (EGFR, ALK, ROS1, KRAS, BRAF, HER2, RET, MET, NTRK1, NTRK2, and NTRK3) in tumor tissue specimens. This enables clinicians to identify multiple genetic markers for potential treatment options based on the National Comprehensive Cancer Network (NCCN) guidelines, 2023.

The test results are highly accurate, with a specificity rate of 100% established through testing negative reference controls and a positive concordance rate of 100% verified by testing positive results. The precision of the kit has also been confirmed through precision references, which yielded acceptable results. 

The analytical sensitivity for detecting mutant alleles (tumor percentage) is 20%. Since the test principle is Real-Time PCR, the results are quick, with reports typically available within 10 days of collecting tissue samples. Tissue samples must have a minimum tumor content of 20%, while needle core biopsies should consist of at least three cores in a single block. Alternatively, six to ten slides with tissue up to 10um (micrometers) thick are also acceptable, provided the tissue is fixed in 10% neutralized buffered formalin with a minimum ischemic time of 15 to 30 minutes.

Commonly reported gene mutations associated with increased cancer risk include BRCA1, BRCA2, TP53, and APC. However, inheriting a cancer susceptibility variant does not guarantee the development of the disease, as there are several influencing factors, such as penetrance, the expressivity of the variant, and lifestyle.

This new test is a significant advancement as it eliminates the need for patients to wait for a month to initiate precision medicine. In addition to the PanPredict Lung Cancer module, the hospital's germline cancer panel testing allows for the simultaneous analysis of several cancer-related genes, including BRCA1, BRCA2, TP53, PTEN, and others associated with an increased risk of developing specific types of cancer such as breast, ovarian, colon, prostate, lung, thyroid, bladder, hepatic cancers, melanoma, glioma, sarcoma, and pancreatic cancer.