What happened, in summary

A young woman developed worsening fatigue, dry cough, chest pain with breathing, and coughing up blood. Imaging found a 5.3 cm mass near the left lung hilum. The mass narrowed the left lower-lobe bronchus and involved a nearby pulmonary artery. She also had a malignant pleural effusion, mediastinal lymph nodes, a liver metastasis, and bone metastases. Biopsy showed ALK fusion-positive lung adenocarcinoma.

She began crizotinib and remained on it for 17 months. Scans then found brain metastases even though she had no neurological symptoms. Treatment changed to alectinib 600 mg twice daily, producing a complete radiologic response. The dose was later reduced to 300 mg twice daily because of elevated bilirubin, while brain-disease control continued.

After 49 months on alectinib, she unexpectedly became pregnant. The possible fetal risks were uncertain, but stopping treatment could have allowed the metastatic cancer to return. After consultation, she chose to continue the reduced dose throughout pregnancy. She had 2 episodes of coughing up blood at about 17 and 24 weeks, but these settled without an invasive procedure. Fetal scans showed normal anatomy and growth.

Her membranes ruptured at 37 weeks, leading to an emergency cesarean delivery. The baby weighed 3,610 g and was healthy at birth. The placenta contained no cancer. Alectinib maintained her complete response and brain control through pregnancy, and the child was meeting expected developmental milestones at 26 months.

She remained under joint oncology and high-risk pregnancy care throughout approximately 36 weeks of fetal exposure to alectinib.