Small Cell Lung Cancer (SCLC)

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This blog is for informational purposes only and should not be taken as medical advice. Content is sourced from third parties, and we do not guarantee accuracy or accept any liability for its use. Always consult a qualified healthcare professional for medical guidance.

What is Small Cell Lung Cancer (SCLC)?

Small Cell Lung Cancer (SCLC) is an aggressive neuroendocrine carcinoma originating from bronchial epithelial cells, accounting for 10-15% of lung cancers. It’s classified as limited-stage (confined to one lung/lymph nodes, 30%) or extensive-stage (spread beyond, 70%). SCLC grows rapidly, with high mitotic rate and early metastasis to brain, liver, bones, and adrenal glands. In 2025, ~30,000 US cases annually, strongly linked to smoking (95%), with median age 65-70, more in men.

Symptoms

Symptoms include persistent cough, chest pain, shortness of breath, wheezing, hemoptysis (coughing blood), hoarseness, and recurrent pneumonia. Paraneoplastic syndromes like Lambert-Eaton (muscle weakness) or Cushing’s (weight gain) occur in 10-20%. Advanced SCLC causes weight loss, fatigue, bone pain (metastases), headaches/seizures (brain spread), or jaundice (liver involvement). Symptoms progress quickly, over weeks.

Causes

Heavy smoking is the primary cause (90-95% of cases), with carcinogens inducing mutations (TP53/RB1 inactivated in 90%). Other risks include radon, asbestos, air pollution, and family history. In 2025, genomic studies show neuroendocrine differentiation and immune suppression as key.

Diagnosis

Diagnosis uses chest X-ray/CT for masses, sputum cytology, bronchoscopy/biopsy for confirmation (small blue cells), and PET-CT/MRI for staging. Brain MRI screens for metastases. Molecular testing (limited utility). In 2025, liquid biopsies detect early relapse.

Treatment

Limited-stage uses chemoradiation (etoposide + cisplatin + radiation), with 25% cure. Extensive-stage uses chemotherapy + immunotherapy (atezolizumab/durvalumab), improving survival by 2-4 months. Prophylactic cranial irradiation reduces brain metastases. In 2025, lurbinectedin and trilaciclib enhance chemo tolerance.

Future Outlook

In 2025, 2-year survival is 45% limited, 10% extensive. Immunotherapy extends to 16 months. By 2030, DLL3-targeted therapies could achieve 25% extensive survival.

Sources

The information for SCLC is sourced from Cleveland Clinic’s “Small Cell Lung Cancer (SCLC): Symptoms, Treatment & Outlook” for symptoms; Mayo Clinic’s “Small cell lung cancer – Symptoms and causes” for causes; NCI’s “Small Cell Lung Cancer Treatment” for treatment; Healthline’s “Small Cell Lung Cancer: Symptoms, Causes, Treatment, and More” for overview; and PMC’s “Advances in Small Cell Lung Cancer” for future outlook.