Histologically, lung cancer can be divided into non-small cell lung cancer and small cell lung cancer, among which, the former accounts for above 85%. The non-small cell lung cancer can be divided into lung adenocarcinoma, squamous carcinoma and large cell carcinoma, among which, the lung adenocarcinoma has the highest incidence, about two thirds of that of primary lung cancer. According to the type and stage, the treatment can be divided into four types: surgery, chemotherapy, radiotherapy and targeted therapy.
Scientific studies have verified that a cancer is caused by the genetic mutation of human body; genetic mutation can lead to infinite proliferation of cells due to losing of normal control ability, eventually resulting in occurrence of cancer. While the targeted drugs can kill the tumor cells carrying specific gene variations, with apparent curative effects, therefore, it is regarded as a first choice for advanced cancer patients in multiple cancer types. Presently, Iressa, Tarceva, Conmana, Xalkori, Afatinib, Ceritinib, Alectinib and Tagrisso have been approved by FDA/CFDA. However, the gene variations carried by different patients are different, which makes patients with different sensitivity, toxic and adverse effects for same antineoplastic drugs.
In American cancer diagnosis and treatment guideline, genes concerning targeted drugs of non-small cell lung cancer are recommended, besides the conventionally commended and detected EGFR and ALK gene variations, BRAF, MET, RET, ROS1 and HER2 are also listed into recommended detection scope. Presently, the commercial targeted drugs have been developed for these gene variations.
The precision diagnosis is a prerequisite for accurate medication. The idea of molecular genotype makes the doctors formulate best therapeutic regimen according to biomarkers carried by lung cancer patients and corresponding clinical status, to greatly find out potentially available targeted drugs and enhance treatment efficiency of antineoplastic drugs.
The occurrence of tumors is often accompanied by multiple gene variations and heterogeneity. As more and more driver genes of lung cancer targets have been found, the traditional single detection technology can’t meet the current detection needs. The second generation sequencing technology can realize parallel detection on multiple genes, saving samples compared to traditional detection methods and reaching higher technology sensitivity, to restore tumor mutation in a more real manner.