Idiopathic pulmonary fibrosis is a poorly prognosed form of progressive interstitial pneumonia. Patients with IPF have a significantly increased risk of developing lung cancer, which further worsens the course of the disease. The most common histological types of LC among patients with IPF are squamous cell carcinoma and adenocarcinoma. Furthermore, all LC treatment modalities can lead to developing an acute IPF exacerbation. In this report, we present a rare case of coexistence of IPF and small cell lung cancer in a 76-year-old patient with chronic obstructive pulmonary disease, and a former smoker. For over 2 years, the patient was treated with an anti-fibrotic drug-pirfenidone, which slowed down the progression of IPF. Unfortunately, after being diagnosed with an active SCLC, the patient was excluded from further participation in the pirfenidone drug program. SCLC is characterized by high aggressiveness, rapid growth and high metastatic potential; therefore, it is necessary to apply antitumor treatment as soon as possible. The described patient was treated with carboplatin-etoposide chemotherapy. Early treatment tolerance was good and after two cycles of cytotoxic treatment, a partial response was present in CT. The presented case emphasizes the need for further research to determine the treatment regimens in patients with coexisting IPF and LC and the appropriateness of antifibrotic treatment in them. In addition, it can help to choose the treatment method for similar patients, indicating a combination of carboplatin and etoposide as an effective and, at the same time, relatively safes method in terms of the risk of IPF's exacerbation.
Keywords: carboplatin–etoposide chemotherapy; idiopathic pulmonary fibrosis (IPF); lung cancer (LC); pirfenidone; small cell lung cancer (SCLC).