[6] Survival can be higher or lower based on a combination of factors including stage, age, sex and race.

Lung cancer is the leading cause of cancer-related deaths worldwide, accounting for the highest mortality rates among both men and women.

Treatment is similar to small cell lung cancer, but survival rates are much higher than other small-cell carcinomas.

Over 70% of patients with small-cell carcinoma present with metastatic disease; common sites include liver, adrenals, bone, and brain.

Ectopic production of large amounts of ADH leads to syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH).

[26] Approximately half of all individuals diagnosed with Lambert–Eaton myasthenic syndrome will eventually be found to have a small-cell carcinoma of the lung.

If images show suspicious spots on patient's lung, a healthcare provider may order chest CT, PET, needle biopsy or bronchoscopy for further check.

However, pathologists can stain lesions with immunohistochemistry Ki-67, CD56, TTF-1, CgA, Syn, P63, CK5/6, LCA, and 34βE12 to help, in order to make a differential diagnosis.

[33] The common metastasis sites of SCLC include lung, brain, bone, adrenal gland, liver, colorectum, and lymph nodes.

[37] In patients with SCLC brain metastasis, the general manifestation on plain CT is of low and medium density, and high-density signals of lesions are rare.

[42] Because SCLC usually metastasizes widely very early on in the natural history of the tumor, and because nearly all cases respond dramatically to chemotherapy and/or radiotherapy, there has been little role for surgery in this disease since the 1970s.

[43] However, in cases of small, asymptomatic, node-negative SCLC's ("very limited stage"), surgical excision may improve survival when used prior to chemotherapy.

[45] Combination chemotherapy consists of a wide variety of agents, including cisplatin, cyclophosphamide, vincristine and carboplatin.

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.

[47] The newer agent lurbinectedin is active in relapsed SCLC and was approved for medical use in the United States in June 2020.

[61] Another type of radiation, prophylactic cranial radiation, prevents central nervous system recurrence and can improve survival in patients with good performance status who have had a complete response or a very good partial response to chemoradiation in LD or chemotherapy in ED.

[65] Lurbinectedin showed increased overall survival rate in relapsed small cell lung cancer in a trial.

[70][71][72] In 2021, the FDA approved trilaciclib (Cosela) as a treatment to reduce the frequency of chemotherapy-induced myelosuppression for patients receiving certain types of chemotherapy for extensive-stage small-cell lung cancer.

[73] As of 2015, 5-year survival rates for small cell lung cancer (extensive and limited) range between 3.6% and 32.2% for women, and between 2.2% and 24.5% for men.

According to the 17th World Conference on Lung Cancer (WCLC), "patients who received chest radiation and prophylactic cranial irradiation along with a mean of five chemotherapy cycles could achieve a median survival of more than 5 years.