Responses in ES-SCLC are often of short duration, and the evidence surrounding the risk of treatment compared to the potential benefit of chemotherapy for people who have extensive SCLC is not clear.If complete response to chemotherapy occurs in a subject with SCLC, then prophylactic cranial irradiation (PCI) is often used in an attempt to prevent the emergence of brain metastases. Although this treatment is often effective, it can cause hair loss and fatigue. Prospective randomized trials with almost two years of follow-up have not shown neurocognitive ill-effects. Meta-analyses of randomized trials confirm that PCI provides significant survival benefits.In August 2018, the FDA approved nivolumab to treat patients with metastatic small cell lung cancer (SCLC) who failed to respond to platinum-based chemotherapy and at least one other line of treatment. Nivolumab is approved in more than 60 countries. According to LUNGevity Foundation, “This approval marks a major milestone for the patients touched by this unrelenting disease and may motivate them to pursue further treatment where there previously were no other approved options.”In September 2018, the results from the global, randomized phase I/III IMpower 133 trial were announced at the World Congress on Lung Cancer in Toronto, ON. In this study, patients with ES-SCLC were treated with standard carboplatin plus etoposide and were randomized to receive atezolizumab or placebo. Atezolizumab was associated with a significant improvement in overall survival (HR for death = 0.70)

Signs and symptoms
Small-cell carcinoma of the lung usually presents in the central airways and infiltrates the submucosa leading to narrowing of bronchial airways.
When the primary site is in the skin, it is referred to as a Merkel-cell carcinoma. Extrapulmonary small-cell carcinoma localized in the lymph nodes
This is an extremely rare type of small cell, and there has been little information in the scientific community. It appears to occur in only one or more lymph nodes, and nowhere else in the body. Treatment is similar to small cell lung cancer, but survival rates are much higher than other small-cell carcinomas. Small-cell carcinoma of the prostate
Small-cell carcinoma of the prostate (SCCP) is a rare form of prostate cancer (approx. 1% of PC). Due to the fact that there is little variation in prostate specific antigen levels, SCCP is normally diagnosed at an advanced stage, after metastasis. Symptomatic metastasis of SCCP to the brain is rare, and carries a poor prognosis. Genetics
TP53 is mutated in 70 to 90% of SCLCs. RB1 and the retinoblastoma pathway are inactivated in most SCLCs. PTEN is mutated in 2 to 10%. MYC amplifications and amplification of MYC family members are found in 30% of SCLCs. Loss of heterozygocity on chromosome arm 3p is found in more than 80% of SCLCs, including the loss of FHIT. One hundred translocations have so far been reported in SCLCs (see the "Mitelman Database" and the Atlas of Genetics and Cytogenetics in Oncology and Haematology,). Diagnosis
When

Localized: the cancer is confined to the lung (aka: limited stage SCLC). Regional: the cancer has spread to lymph nodes (or glands) within the chest (between limited and extensive stage SCLC).