Home >> ALL ISSUES >> 2014 Issues >> Anatomic Pathology Selected Abstracts, 2/14

Anatomic Pathology Selected Abstracts, 2/14

image_pdfCreate PDF

Anatomic pathology abstracts editors: Michael Cibull, MD, professor of pathology, University of Kentucky, Lexington; Rouzan Karabakhtsian, MD, attending pathologist, Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY; Thomas Cibull, MD, dermatopathologist, Evanston Hospital, NorthShore University HealthSystem, Evanston, Ill.; and Rachel Stewart, DO, resident physician, Department of Pathology and Laboratory Medicine, University of Kentucky.

Early stage triple-negative breast cancer treated with mastectomy without adjuvant radiotherapy

The authors conducted a study to evaluate and identify patterns of failure and prognostic factors for locoregional recurrence that could justify postmastectomy radiotherapy after modified radical mastectomy in patients with early stage triple-negative breast cancer. Between January 2000 and July 2007, the authors retrospectively analyzed 390 patients who had triple-negative breast cancer with T1/T2 tumors and from zero to three positive lymph nodes (pathologic T1-T2N0-N1) and who underwent modified radical mastectomy without postmastectomy radiotherapy at the authors’ institution. The five-year cumulative incidence for events was calculated using Kaplan-Meier analysis, and subgroups were compared using the log-rank test. Multivariate analysis was performed using a Cox proportional hazards model. Overall, 86.4 percent of patients received chemotherapy. At a median followup of 60.5 months, the five-year cumulative rates of local recurrence, regional recurrence, locoregional recurrence, and distant metastasis were 5.4 percent, 4.7 percent, eight percent, and 13.4 percent, respectively. On multivariate analysis, age younger than 50 years, presence of lymphovascular invasion, grade 3 tumor, and three involved lymph nodes were significantly associated with an increased risk of locoregional recurrence. The five-year locoregional recurrence rate for patients who had zero or one risk factor, two risk factors, and three or four risk factors was 4.2 percent, 25.2 percent, and 81 percent (P<0.0001), respectively. The presence of lymphovascular invasion and having three involved lymph nodes were statistically significant predictors of regional recurrence, and the patients who had regional recurrence had a significantly greater risk of distant metastases compared with patients who had local recurrence (59.1 percent versus 20.9 percent; P<0.0001). The authors concluded that several risk factors were identified in this study that correlated independently with a greater incidence of locoregional recurrence in patients who had early stage triple-negative breast cancer. The results indicated that postmastectomy radiotherapy should be considered for those patients who have two or more of these factors.

Chen X, Yu X, Chen J, et al. Analysis in early stage triple-negative breast cancer treated with mastectomy without adjuvant radiotherapy: Patterns of failure and prognostic factors. Cancer. 2013;119(13):2366–2374.

Correspondence: Dr. Xiaomao Guo at guoxiaomao188@gmail.com

Predicting recurrence after limited resection versus lobectomy for small lung adenocarcinoma

The authors analyzed the prognostic significance of the new International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) lung adenocarcinoma classification for patients undergoing resection for small (2 cm or less) lung adenocarcinoma and to investigate whether histologic subtyping can predict recurrence after limited resection (LR) versus lobectomy (LO). Comprehensive histologic subtyping was performed according to the IASLC/ATS/ERS classification on all consecutive patients who underwent limited resection or lobectomy for small lung adenocarcinoma between 1995 and 2009 at Memorial Sloan-Kettering Cancer Center. Clinical characteristics and pathologic data were retrospectively evaluated for 734 consecutive patients (LR, 258; LO, 476). Cumulative incidence of recurrence (CIR) was calculated using competing risks analysis and compared across groups using Grey’s test. All statistical tests were two-sided. Application of IASLC/ATS/ERS lung adenocarcinoma histologic subtyping to predict recurrence demonstrates that, in the limited resection group but not the lobectomy group, a micropapillary component of five percent or greater was associated with an increased risk of recurrence, compared with a micropapillary component of less than five percent (LR: five-year CIR, 34.2 percent; 95 percent confidence interval [CI], 23.5–49.7 percent versus five-year CIR, 12.4 percent; 95 percent CI, 6.9–22.1 percent; P<0.001/LO: five-year CIR, 19.1 percent; 95 percent CI, 12–30.5 percent versus 15-year CIR, 12.9 percent; 95 percent CI, 7.6–21.9 percent; P=0.13). In the limited resection group, among patients with tumors with a micropapillary component of five percent or greater, most recurrences (63.4 percent) were locoregional. A micropapillary component of five percent or greater was statistically significantly associated with increased risk of local recurrence when the surgical margin was less than 1 cm (five-year CIR, 32 percent; 95 percent CI, 18.6–46 percent for micropapillary of five percent or greater versus five-year CIR, 7.6 percent; 95 percent CI, 2.3–15.6 percent for micropapillary of less than five percent; P=0.007) but not when the surgical margin was 1 cm or greater (five-year CIR, 13 percent; 95 percent CI, 4.1–22.1 percent for micropapillary of five percent or greater versus five-year CIR, 3.4 percent; 95 percent CI, zero–7.7 percent for micropapillary of less than five percent; P=0.10). The authors concluded that application of the IASLC/ATS/ERS classification identifies a micropapillary component of five percent or greater as independently associated with risk of recurrence in patients treated with limited resection.

Nitadori J, Bograd AJ, Kadota K, et al. Impact of micropapillary histologic subtype in selecting limited resection vs lobectomy for lung adenocarcinoma of 2 cm or smaller. J Natl Cancer Inst. 2013;105(16):1212–1220.

Correspondence: Dr. Prasad S. Adusumilli at adusumip@mskcc.org

HER2 amplification in gastric cancer: a rare event restricted to intestinal phenotype

The authors conducted a study to identify HER2 prevalence in gastric cancer and correlate it with location, phenotype, and followup. Immunohistochemistry (IHC) with the Hercep Test was performed for consecutive gastric cancer patients who provided tissue blocks, gross data, and followup data. Chromogenic and fluorescence in situ hybridization were performed on IHC-positive tumors from 269 patients (median age, 61 years). In 172 gastrectomized patients, histotypes were diffuse (72; 41.8 percent), intestinal (63; 36.6 percent), and mixed (37; 21.5 percent). HER2 IHC expression was zero in 167, 2+ in two, and 3+ in three tumors. Only endoscopic biopsies were available in 97 patients, and HER2 IHC expression was zero in 88, 1+ in three, 2+ in four, and 3+ in two patients. Ten of the 269 tumors (3.7 percent) had HER2 amplification. Amplified tumors were intestinal adenocarcinomas located throughout the various regions of the stomach. Heterogeneity was documented in four widely sampled tumors. HER2 amplification was restricted to the intestinal phenotype. It is a rare event, and its screening should be driven by gastric cancer histotype.

Cruz-Reyes C, Gamboa-Dominguez A. HER2 amplification in gastric cancer is a rare event restricted to the intestinal phenotype. Int J Surg Pathol. 2013;21(3):240–246.

Correspondence: Dr. Armando Gamboa-Dominguez at agamboad@gmail.com

Gleason score undergrading on biopsy sample of prostate cancer

The authors conducted a population-based study to investigate the degree of concordance between Gleason scores obtained from prostate biopsies and those obtained from prostatectomy specimens, as well as the determinants of biopsy understaging. The study included all 371 prostate cancer patients recorded at the Geneva Cancer Registry, diagnosed from 2004 to 2006, who underwent a radical prostatectomy. Kappa statistics were used to evaluate the Gleason score concordance from biopsy and prostatectomy specimens. Logistic regression was used to determine the parameters that predict undergrading of Gleason score in prostate biopsies. The kappa statistic between biopsy and prostatectomy Gleason score was 0.42 (P<0.0001), with 67 percent of patients matched exactly and 26 percent (n=95) of patients with Gleason score underestimated by biopsy. In a multi-adjusted model, biopsy undergrading was independently associated with increasing age, advanced clinical stage, having fewer than 10 biopsy cores, and longer delay between the two procedures. In particular, the proportion of exact matches increased to 72 percent when the patients had 10 or more needle biopsy cores. The main limitation of the study was that biopsy and prostatectomy specimens were examined by different laboratories. The authors concluded that the data show that concordance between biopsy and prostatectomy Gleason scores lies within the classic clinical standards in this population-based study. The number of biopsy cores appears to strongly impact concordance between biopsy and radical prostatectomy Gleason score.

Rapiti E, Schaffar R, Iselin C, et al. Importance and determinants of Gleason score undergrading on biopsy sample of prostate cancer in a population-based study. BMC Urol. 2013;13:19 or www.biomedcentral.com/1471-2490/13/19

Correspondence: Elisabetta Rapiti at elisabetta.rapiti@unige.ch

Fallopian tube intraluminal tumor spread from noninvasive precursor lesions

Pelvic serous carcinoma is usually advanced stage at diagnosis, indicating that abdominal spread occurs early in carcinogenesis. Recent discovery of a precursor sequence in the fallopian tube, culminating in serous tubal intraepithelial carcinoma (STIC), provides an opportunity to study early disease events. The authors conducted a study to explore novel metastatic routes in STICs. A BRCA1 mutation carrier (patient A) who presented with a STIC and tubal intraluminal shedding of tumor cells on prophylactic bilateral salpingo-oophorectomy (PBSO) instigated scrutiny of an additional 23 women who underwent PBSO and 40 patients with pelvic serous carcinoma involving the fallopian tubes. Complete serial sectioning of the tubes and ovaries of patient A did not reveal invasive carcinoma, but subsequent staging surgery showed disseminated abdominal disease. STIC, intraluminal tumor cells, and abdominal metastases displayed an identical immunohistochemical profile (p53/WT1/PAX8/PAX2) and TP53 mutation. In 16 serous carcinoma patients (40 percent), tubal intraluminal tumor cells were found, while none were found in the PBSO group. This is the first description of an STIC that plausibly metastasized without invasion, through intraluminal shedding of malignant surface epithelial cells in the fallopian tube, and subsequently spread throughout the peritoneal cavity. These findings warrant reconsidering the malignant potential of STICs and indicate that intraluminal shedding could be a risk factor for early intraperitoneal metastasis. Although rare in the absence of invasive cancer, the authors showed that intraluminal shedding of tumor cells in the fallopian tubes of women with serous carcinoma is common and a likely route of abdominal spread.

Bijron JG, Seldenrijk CA, Zweemer RP, et al. Fallopian tube intraluminal tumor spread from noninvasive precursor lesions: a novel metastatic route in early pelvic carcinogenesis. Am J Surg Pathol. 2013;37(8):1123–1130.

Correspondence: Dr. Paul J. van Diest at p.j.vandiest@umcutrecht.nl

CAP TODAY
X