[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.

Over 70% of patients with small-cell carcinoma present with metastatic disease; common sites include the 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 the 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 the 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 very good partial response to chemoradiation in LD or chemotherapy in ED.

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

[67][68][69] Trilaciclib, a CKD4/6 inhibitor, reduces chemotherapy-induced toxicity in patients being treated for small-cell lung cancer.

[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.