PURPOSE: Chemo-sensitivity for metastatic lesion of cancer often differs from that of primary lesion, but there are few reports investigated about this phenomenon. We studied chemo-sensitivity tests on both primary lesions and the metastatic lymph nodes of resected non-small cell lung cancer (NSCLC, pN1-2) and evaluated the differences.
METHODS: Operative specimens were obtained in 13 patients with NSCLC (6 Squamous cell carcinoma; SQ, 7 adenocarcinoma; AD) whose lymph nodes were confirmed as positive for metasitasis by frozen section. Both the primary tumor and metastatic lymph node from the same patient were examined immediately after resection. We used the collagen gel embedded culture drug sensitivity test (CD-DST) as the chemo-sensitivity test for 6 anticancer drugs (5FU, CDDP, GEM, TXT, VNR, SN38). When growth rate, which was determined by the T/C ratio (T; the signal for the viable cells in treated group, C; the signal in control), was less than 50%, we regarded as sensitive for the drug.
RESULTS: There were only 4 cases (2SQ, 2AD), in which chemo-sensitivity was exactly the same between the primary lesions and metastatic lymph nodes. In SQ cases, chemo-sensitivity of the primary lesions to 5FU tended to be consistent with that of the metastatic lymph nodes. In contrast, in 4 of the 7 cases with AD, primary lesions were negative for the chemo-sensitivity to 5FU but metastatic lymph nodes were sensitive.
CONCLUSION: In many cases in this series, the chemo-sensitivity of the primary tumor differed from that of metastatic lymph nodes to each anti-cancer drug. In AD cases, chemo-sensitivities of metastatic lymph nodes to 5FU were significantly higher than those of primary lesions.
CLINICAL IMPLICATIONS: The chemo-sensitivity of the metastatic lesions should be considered as well as that of the primary lesion when deciding upon agents used for postoperative chemotherapy.
DISCLOSURE: Masahiko Takata, None.