Abstract 946P
Background
LN examination among eNSCLC patients (pts) is critical in fulfilling the IASLC complete resection criteria and in perioperative chemotherapy decisions. Previous studies have shown that LN non-examination is associated with overall survival rates similar to pts with LN metastasis, presumably due to inadequate adv treatment (tx). This study evaluated the prevalence of LN exam and adv tx in US Medicare eNSCLC pts.
Methods
This retrospective observational study identified pts with stage IA-IIIB NSCLC (AJCC 7th ed) from SEER data linked with Medicare claims. Pts were ≥65 years at diagnosis between January 2010 and December 2017, had surgery within 1 month prior or 12 months after diagnosis and were continuously enrolled in Medicare Parts A and B ≥6 months before diagnosis. Additional continuous enrollment criteria of Medicare Parts A, B and D ≥6 months post-surgery or up to date of death was required for adv tx outcomes. Pts were grouped by LN exam status: none (pNX), no LN metastasis after LN exam (pN0) or LN metastasis after exam (pN1/2). Adv tx was identified within 6 months or up to death post-surgery. Descriptive statistics were used to summarize results.
Results
A total of 14,684 pts were included; 1596 (11%) were pNX, 9943 (68%) were pN0 and 3145 (21%) were pN1/2. The proportion of pNX pts decreased from 14% in 2010 to 8% in 2017. A mean (SD) of 11 (9) LNs were examined (median, 9; IQR, 5-15). Adv chemotherapy was identified in 21% (pNX), 13% (pN0) and 63% (pN1/2) of pts. Wedge resections were performed in 47% (pNX), 18% (pN0) and 11% (pN1/2) of pts.
Conclusions
LN examination in Medicare pts with eNSCLC has improved over time with a sufficient number of excised LNs at resection. However, many resections continue to lack LN evaluation and pNX was associated with lower adv chemotherapy utilization rates than pN1/2, which further supports that pNX may negatively impact adv tx decisions. Table: 946P
| Variable, n (%) | pNX n=1596 | pN0 n=9943 | pN1/2 n=3145 |
| Extent of lung cancer resection | |||
| Pneumonectomy | 17 (1) | 150 (2) | 218 (7) |
| Bilobectomy | <11 | 103 (1) | 71 (2) |
| Lobectomy | 255 (16) | 6149 (62) | 1985 (63) |
| Wedge resection | 746 (47) | 1795 (18) | 347 (11) |
| Segmentectomy | 134 (8) | 873 (9) | 147 (5) |
| Other surgery | 237 (15) | 141(1) | 71 (2) |
| Surgery | |||
| Robotic-assisted thoracic surgery | 31 (2) | 307 (3) | 74 (2) |
| Video-assisted thoracic surgery | 12 (<1) | <11 | <11 |
| Thoracotomy | 192 (12) | 502 (5) | 216 (7) |
| Sternotomy | 19 (1) | 21 (<1) | 32 (1) |
| pNX n=996 | pN0 n=6476 | pN1/2 n=1999 | |
| Received adj tx | |||
| Chemotherapy | 211 (21) | 846 (13) | 1255 (63) |
| Immunotherapy | <11 | <11 | 21 (1) |
| Targeted therapy | 25 (3) | 43 (1) | 48 (2) |
| Chemoradiation | 118 (12) | 197 (3) | 494 (25) |
| Radiation | 245 (25) | 510 (8) | 652 (33) |
Clinical trial identification
Editorial acknowledgement
Support for third-party writing assistance for this abstract, furnished by Jeff Frimpter, MPH, of Health Interactions Inc, was provided Genentech Inc.
Legal entity responsible for the study
Genentech, Inc.
Funding
Genentech, Inc.
Disclosure
J.M. Lee: Financial Interests, Personal, Advisory Role: Bistol Meyers Squibb; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Advisory Board, Advisory Board and Steering Committee: Genentech/Roche, Novartis; Financial Interests, Personal, Other, Consultant: Genetech/Roche, Novartis; Financial Interests, Institutional, Research Grant: Merck. C.S. Meyer: Financial Interests, Personal, Full or part-time Employment: Genentech, Inc.; Financial Interests, Personal, Stocks/Shares: Genentech, Inc. T.M. To: Financial Interests, Personal, Full or part-time Employment: Genentech, Inc.; Financial Interests, Personal, Stocks/Shares: Genentech, Inc. C. Lin: Financial Interests, Personal, Full or part-time Employment: Genentech, Inc.; Financial Interests, Personal, Stocks/Shares: Genentech, Inc. A. Johnson: Financial Interests, Personal, Full or part-time Employment: Genentech, Inc.; Financial Interests, Personal, Stocks/Shares: Genentech, Inc. J.S. Lee: Financial Interests, Personal, Full or part-time Employment: Genentech, Inc.; Financial Interests, Personal, Stocks/Shares: Genentech, Inc. All other authors have declared no conflicts of interest.