Evolution in the Surgical Care of Patients With Non-Small Cell Lung Cancer in the Mid-South Quality of Surgical Resection Cohort

Surgery is the most important curative treatment modality for patients with early-stage non-small cell lung cancer (NSCLC). We examined the pattern of surgical resection for NSCLC in a high incidence and mortality region of the United States over a 10-year period (2004-2013) in the context of a regional surgical quality improvement initiative. We abstracted patient-level data on all resections at 11 hospitals in 4 contiguous Dartmouth Hospital Referral Regions in North Mississippi, East Arkansas, and West Tennessee. Surgical quality measures focused on intraoperative practice, with emphasis on pathologic nodal staging. We used descriptive statistics and trend analyses to assess changes in practice over time. To measure the effect of an ongoing regional quality improvement intervention with a lymph node specimen collection kit, we used period effect analysis to compare trends between the preintervention and postintervention periods. Of 2566 patients, 18% had no preoperative biopsy, only 15% had a preoperative invasive staging test, and 11% underwent mediastinoscopy. The rate of resections with no mediastinal lymph nodes examined decreased from 48%-32% (P < 0.0001), whereas the rate of resections examining 3 or more mediastinal stations increased from 5%-49% (P < 0.0001). There was a significant period effect in the increase in the number of N1, mediastinal, and total lymph nodes examined (all P < 0.0001). A quality improvement intervention including a lymph node specimen collection kit shows early signs of having a significant positive effect on pathologic nodal examination in this population-based cohort. However, gaps in surgical quality remain.

The impact of a novel lung gross dissection protocol on intrapulmonary lymph node retrieval from lung cancer resection specimens

Although thorough pathologic nodal staging provides the greatest prognostic information in patients with potentially curable non-small cell lung cancer, N1 nodal metastasis is frequently missed. We tested the impact of corrective intervention with a novel pathology gross dissection protocol on intrapulmonary lymph node retrieval. This study is a retrospective review of consecutive lobectomy, or greater, lung resection specimens over a period of 15 months before and 15 months after training pathologist's assistants on the novel dissection protocol. One hundred forty one specimens were examined before and 121 specimens after introduction of the novel dissection protocol. The median number of intrapulmonary lymph nodes retrieved increased from 2 to 5 (P<.0001), and the 75th to 100th percentile range of detected intrapulmonary lymph node metastasis increased from 0 to 5 to 0 to 17 (P=.0003). In multivariate analysis, the extent of resection, examination period (preintervention or postintervention), and pathologic N1 (vs N0) status were most strongly associated with a higher number of intrapulmonary lymph nodes examined. A novel pathology dissection protocol is a feasible and effective means of improving the retrieval of intrapulmonary lymph nodes for examination. Further studies to enhance dissemination and implementation of this novel pathology dissection protocol are warranted.

Number of lymph nodes associated with maximal reduction of long-term mortality risk in pathologic node-negative non-small cell lung cancer

BACKGROUND

Forty-four percent of patients with pathologic node negative (pN0) non-small cell lung cancer (NSCLC) die within 5 years of curative-intent surgical procedures. Heterogeneity in pathologic nodal examination practice raises concerns about the accuracy of nodal staging in these patients. We hypothesized a reciprocal relationship between the number of lymph nodes examined and the probability of missed lymph node metastasis and sought to identify the number of lymph nodes associated with the lowest mortality risk in pN0 NSCLC.

METHODS

We analyzed resections for first primary pN0 NSCLC in the United States Surveillance, Epidemiology, and End Results (SEER) database from 1998 to 2009, with survival updated to December 31, 2009.

RESULTS

In 24,650 eligible patients, there was a significant sequential reduction in mortality risk with examination of more lymph nodes. The lowest mortality risk occurred in those with 18 to 21 lymph nodes examined. The hazard ratio for all-cause mortality was 0.65 and the 95% confidence interval (CI) was 0.57 to 0.73; for lung cancer-specific mortality, hazard ratio was 0.62 and CI was 0.53 to 0.73 (p<0.001 for both). The median number of lymph nodes examined was only 6.

CONCLUSIONS

Lymph node evaluation falls far short of optimal in patients with resected pN0 NSCLC, raising the odds of underestimation of long-term mortality risk and failure to identify candidates for postoperative adjuvant therapy. This represents a major quality gap for which corrective intervention is warranted.

Incomplete Intrapulmonary Lymph Node Retrieval After Routine Pathologic Examination of Resected Lung Cancer

Purpose

Pathologic nodal stage affects prognosis in patients with surgically resected non–small-cell lung cancer (NSCLC). Unlike examination of mediastinal lymph nodes (LNs), which depends on surgical practice, accurate examination of intrapulmonary (N1) nodes depends primarily on pathology practice. We investigated the completeness of N1 LN examination in NSCLC resection specimens and its potential impact on stage.

Patients and Methods

We performed a case-control study of a special pathologic examination (SPE) protocol using thin gross dissection with retrieval and microscopic examination of all LN-like material on remnant NSCLC resection specimens after routine pathologic examination (RPE). We compared LNs retrieved by the SPE protocol with nodes examined after RPE of the same lung specimens and with those of an external control cohort.

Results

We retrieved additional LNs in 66 (90%) of 73 patient cases and discovered metastasis in 56 (11%) of 514 retrieved LNs from 27% of all patients. We found unexpected LN metastasis in six (12%) of 50 node-negative patients. Three other patients had undetected satellite metastatic nodules. Pathologic stage was upgraded in eight (11%) of 73 patients. The time required for the SPE protocol decreased significantly with experience, with no change in the number of LNs found.

Conclusion

Standard pathology practice frequently leaves large numbers of N1 LNs unexamined, a clinically significant proportion of which harbor metastasis. By improving N1 LN examination, SPE can have an impact on prognosis and adjuvant management. We suggest adoption of the SPE to improve pathologic staging of resected NSCLC.