DETECTION OF OCCULT BONE-MARROW MICROMETASTASES IN PATIENTS WITH OPERABLE LUNG-CARCINOMA

Objectives A large proportion oi patients with operable lung carcinoma (no evidence of systemic spread of tumor) develop metastatic disease after primary therapy. More sensitive and specific methods are needed to identify patients at highest risk for recurrence who may benefit mo st from adjuvant therapy, while sparing those patients who do not requ ire such treatment. Summary Background Data Using epithelial-specific monoclonal antibodies, the authors have developed an immunocytochemica l assay capable of detecting as few as 2 lung cancer cells in 1 millio n bone marrow cells. Methods The assay was used to test the bone marro w (from resected ribs) of 43 patients with primary nonsmall cell lung carcinoma who showed no clinical or pathologic evidence of systemic di sease. Results Occult bone marrow micrometastases (BMMs) were detected in 40% of patients (17/43) with non-small cell lung cancer, including 29% (5/17) of patients with stage I or II disease and 46% of whom (12 /26) had stage Ill disease. The median follow-up was 13.6 months. Pati ents with occult BMMs had significantly shorter times to disease recur rence compared with patients without BMMs (7.3 vs. >35.1 months, p = 0 .0009). Furthermore, for patients with stage I or II disease, the pres ence of occult BMMs was significantly associated with a higher rate of recurrence (p = 0.0004). Conclusions The detection of occult BMMs ide ntifies patients with operable non-small cell lung carcinoma who are a t significantly increased risk for recurrence, independent of tumor st age, and may be useful in evaluating patients for adjuvant treatment p rotocols.