Author of

• 10923

  +

  P1.18 - Poster Session 1 - Pathology (ID 175)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Pathology
  • Presentations: 2
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10939

    +

    P1.18-016 - The association between size and histology in discarded intrapulmonary lymph nodes (LN) from non-small cell lung cancer (NSCLC) resection specimens: can we select nodes for examination by their size? (ID 2996)

    09:30 - 09:30  |  Author(s): R.U. Osarogiagbon
    • Abstract

    Background
    Pathologic nodal staging is the most important prognostic factor in resected NSCLC, but LN yields are low. A median of 3 N1 nodes are examined in US lung resection specimens, though fastidious examination yields a median of 11 N1 LN. A bias towards examination of larger nodes may cause understaging when small LN with metastasis are missed. We examined the size and histologic characteristics of LN material retrieved during a fastidious redissection of discarded lung cancer resection specimens.

    Methods
    Prospective study of lobectomy specimens discarded after completion of the routine pathology examination. A fastidious redissection protocol was used to retrieve all grossly LN-like material for histologic examination, irrespective of size. The Wilcoxon-Mann-Whitney test was used to compare the materials with and without metastasis.

    Results
    1094 LN-like materials retrieved from 112 resection specimens: 345 (32%) were not LN on histologic examination (including 11 satellite metastatic nodules); 749 (68%) were LN, of which 71 (9%) had metastasis. The distribution of size and histology is shown (Figure). The median size (range) of the non-LN, LN without metastasis, and LN with metastasis was: 4.0 (0.9 - 20); 6.0 (1.0 - 27), 12.0 (1.0 - 27) mm (p<.0001, for all comparisons). Twenty-six patients (23%) had LN with metastasis (see histogram). In 4 patients, LN with metastasis were smaller than LN without metastasis.Figure 1Figure 2

    Conclusion
    Despite the statistically significant tendency for LN with metastasis to be larger than those without metastasis, there was broad size distribution overlap. Furthermore, a third of materials that grossly appeared to be LN were not, though some were satellite metastatic nodules. This probably contributes to the relatively low LN yield in routine examinations. LN size is not a reliable means of distinguishing between those with and without metastasis. The protocol for gross N1 LN retrieval should be modified to facilitate a more thorough routine examination.

  • 10940

    +

    P1.18-017 - The prevalence of micrometastasis (MM) in discarded intrapulmonary lymph nodes (LN) in resected non-small cell lung cancer (NSCLC). (ID 3000)

    09:30 - 09:30  |  Author(s): R.U. Osarogiagbon
    • Abstract

    Background
    44% of pN0 NSCLC resection patients die within 5 years. We recently showed 12% of pN0 NSCLC resection specimens have discarded LN with metastasis on H&E microscopy. ACOSOG Z0040 demonstrated the prognostic impact of immunohistochemistry positive (IHC+) LN MM. In this report, we investigated the prevalence of IHC+ LN MM in patients with and without H&E + LN metastasis in discarded lung resection specimens.

    Methods
    Using a fastidious redissection special pathology examination (SPE) protocol, we retrieved LN from discarded NSCLC resection specimens after the routine pathology examination (RPE). All retrieved LN were examined for metastasis by H&E light microscopy. We matched 26 patients with 1 or more H&E+ LN (irrespective of whether detected on RPE or SPE) with 28 patients without detectable nodal metastasis. Fresh sections were cut from all retrieved LN tissue blocks of these 54 patients and stained with AE1/AE3 immunostain (Dako) at an independent institution. All slides were examined independently by pathologists at two different institutions, and discordant reports resolved at a consensus review session. The prevalence of IHC positivity was determined from the final consensus of pathologists.

    Results
    Figure 1

    Conclusion
    Micrometastatic disease is evident in a significant proportion of the LN retrieved from discarded NSCLC resection specimens, further extending the potential clinical implications of incomplete LN examination. IHC+ nodes were not found in LN from patients with H&E negative disease after fastidious examination by SPE. The survival implications of these findings will be investigated in future clinical trials.

• 11595

  +

  P2.07 - Poster Session 2 - Surgery (ID 190)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Surgery
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11629

    +

    P2.07-034 - Audit of mediastinal lymph node (MLN) examination in non-small cell lung cancer (NSCLC) resections using a specimen collection kit and checklist intervention. (ID 2854)

    09:30 - 09:30  |  Author(s): R.U. Osarogiagbon
    • Abstract

    Background
    Optimal pathologic nodal staging of NSCLC requires MLN dissection (MLND) or systematic sampling (SS). In our prior audit of a citywide database, 45% of resections were claimed by surgeons as MLND, none of which met pathology criteria, only 9% of all resections met SS criteria, 50% of all resections had random sampling (RS) and 42% had no sampling (NS) of MLN. An independent surgeon audit suggested that 29% of operation notes described a MLND, but 26% were RS and 45% NS. The concordance rate for MLND or SS between surgeon claims and pathology report audit was only 11%. We examined the impact of corrective intervention with a pre-labeled lymph node specimen collection kit and a checklist on the verifiable quality of MLN examination in a repeat audit of surgeon claims.

    Methods
    Prospective cohort study of NSCLC resections performed with the kit at 4 Memphis, TN hospitals from 11/2010 - 01/2013. Surgeons, operating room and pathology staff received training on the value of rigorous MLN examination and proper kit use. Surgeons marked the stations harvested on a checklist during the operation. Resections were classified into 4 pre-defined groups based on MLN stations marked on the checklist (surgeon claims), and the pathology report: MLND, SS (both by ACOSOG Z0030 trial criteria), RS (>0 MLN present, but MLND/SS criteria not met), NS (0 MLN present). Audited operation notes were categorized by surgeons from two independent academic cancer centers into one of the 4 MLN examination groups. The primary endpoints were the verifiable rate of MLND + SS and the concordance rate between observers.

    Results
    N = 161; 51% female, median Charlson comorbidity score 2 (IQR 1-3), 58% right-side resections. Clinico-demographic characteristics were similar between patients in each MLN category. Surgeons claimed MLND in 49%, SS in 9% of cases; vs 76% and 14% in the independent surgeon audit. The kappa score between independent surgeons was 0.44 ('moderate agreement'). Figure 1

    Conclusion
    The verifiable MLND+SS rate increased from 9% in the previous pathology audit to 83%; and from 29% in the previous independent surgeon audit to 89%. Concordance between operating surgeon claims and the pathology report increased from 11% to 83%. The improved lymph node yield and verifiable quality of MLN mapping indicates that implementing a corrective intervention with a pre-labelled specimen collection kit and checklist improves surgical MLN collection practice, fosters better communication with pathologists and improves the quality of pathologic nodal staging of NSCLC.