HER2-low breast cancer shows a lower immune response compared to HER2-negative cases.

Currently, the human epidermal growth factor receptor 2 (HER2) status of breast cancer is classified dichotomously as negative or positive to select patients for HER2-targeted therapy. However, with the introduction of novel treatment options, it is important to get more insight in the biology of cancers with low HER2 expression. Therefore, we studied several clinicopathologic characteristics in relation to the level of HER2 expression (HER2- versus HER2low). We used a well-documented cohort of breast cancer patients (n = 529), with available tissue microarrays and Affymetrix mRNA expression data. HER2 status was scored as negative (immunohistochemistry 0) or low (immunohistochemistry 1 + or 2 + without amplification). We associated HER2 status with several clinicopathologic characteristics, gene-expression data and survival, stratified for estrogen receptor (ER) status. Overall, breast cancers were scored as HER2- (n = 429) or HER2low (n = 100). Within the ER+ cohort (n = 305), no significant associations were found between the HER2 groups and clinicopathologic features. However, HER2low tumors showed several differentially expressed genes compared to HER2- cases, including genes that are associated with worse outcome and depletion of immunity. In ER- cases (n = 224), HER2low status was significantly associated with increased regional nodal positivity, lower density of tumor infiltrating lymphocyte and a lower protein expression of Ki-67 and EGFR compared to HER2- cases. After multivariate analysis, only density of tumor infiltrating lymphocytes remained significantly associated with HER2low status (P = 0.035). No difference in survival was observed between HER2low and HER2- patients, neither in the ER+ nor ER- cohort. In conclusion, our data suggests that HER2low breast cancer is associated with a lower immune response compared to HER2- breast cancer.

Large and small cribriform architecture have similar adverse clinical outcome on prostate cancer biopsies.

AIMS: Invasive cribriform and intraductal carcinoma (IDC) are associated with adverse outcome in prostate cancer patients, with the large cribriform pattern having the worst outcome in radical prostatectomies. Our objective was to determine the impact of the large and small cribriform patterns in prostate cancer biopsies. METHODS AND RESULTS: Pathological revision was carried out on biopsies of 1887 patients from the European Randomised Study of Screening for Prostate Cancer. The large cribriform pattern was defined as having at least twice the size of adjacent benign glands. The median follow-up time was 13.4 years. Hazard ratios for metastasis-free survival (MFS) and disease-specific survival (DSS) were calculated using Cox proportional hazards regression. Any cribriform pattern was found in 280 of 1887 men: 1.1% IDC in grade group (GG) 1, 18.2% in GG2, 57.1% in GG3, 55.4% in GG4 and 59.3% in GG5; the large cribriform pattern was present in 0, 0.5, 9.8, 18.1 and 17.3%, respectively. In multivariable analyses, small and large cribriform patterns were both (P < 0.005) associated with worse MFS [small: hazard ratio (HR) = 3.04, 95% confidence interval (CI) = 1.93-4.78; large: HR = 3.17, 95% CI = 1.68-5.99] and DSS (small: HR = 4.07, 95% CI = 2.51-6.62; large: HR = 4.13, 95% CI = 2.14-7.98). Patients with the large cribriform pattern did not have worse MFS (P = 0.77) or DSS (P = 0.96) than those with the small cribriform pattern. CONCLUSIONS: Both small and large cribriform patterns are associated with worse MFS and DSS in prostate cancer biopsies. Patients with the large cribriform pattern on biopsy have a similar adverse outcome as those with the small cribriform pattern.

Updating the Rotterdam Prostate Cancer Risk Calculator with Invasive Cribriform and/or Intraductal Carcinoma for Men with a Prior Negative Biopsy.

The Rotterdam Prostate Cancer Risk Calculator (RPCRC) is a well-validated tool for upfront risk stratification to reduce the number of prostate biopsies and magnetic resonance imaging scans among both biopsy-naïve and previously biopsied men. The presence of invasive cribriform and/or intraductal carcinoma (CR/IDC) identifies men with aggressive grade group (GG) 2 tumors. This finding was recently incorporated in the RPCRC for biopsy-naïve men to predict the probability of no PCa, indolent PCa (GG 1 disease and GG 2 disease without CR/IDC), and clinically significant PCa (csPCa: GG 2 disease with CR/IDC and higher). The aim of the current study was to update the RPCRC for men with a previous negative biopsy with the presence of CR/IDC. A total of 2215 men were eligible for analyses, of whom 1776 (80%) were not diagnosed with PCa, 358 (16%) were diagnosed with indolent PCa, and 81 (4%) were diagnosed with csPCa according to the original 2014 Gleason grading. The optimism-corrected area under the curve was 0.69 for any PCa and 0.77 for csPCa. With a threshold of 10% for indolent PCa or 1% for csPCa, 20% of all prostate biopsies could be avoided and 2% of all csPCa cases would be missed. Our results support upfront risk stratification with the updated RPCRC. PATIENT SUMMARY: Risk stratification for men without a prior diagnosis of prostate cancer can reduce the number of prostate biopsies and magnetic resonance imaging scans carried out in this patient population. Our study shows that it is possible to update the Rotterdam Prostate Cancer Risk Calculator for men with a previous negative biopsy with the presence of invasive cribriform and/or intraductal carcinoma.

Comedonecrosis Gleason pattern 5 is associated with worse clinical outcome in operated prostate cancer patients.

Individual growth patterns and cribriform architecture are increasingly considered in risk stratification and clinical decision-making in men with prostate cancer. Our objective was to establish the prognostic value of individual Gleason 5 patterns in a radical prostatectomy (RP) cohort. We reviewed 1064 RPs and recorded Grade Group (GG), pT-stage, surgical margin status, Gleason 4 and 5 growth patterns as well as intraductal carcinoma. The clinical endpoints were biochemical recurrence and post-operative distant metastasis. Gleason pattern 5 was present in 339 (31.9%) RPs, of which 47 (4.4%) presented as primary, 166 (15.6%) as secondary, and 126 (11.8%) as tertiary pattern. Single cells/cords were present in 321 (94.7%) tumors with Gleason pattern 5, solid fields in 90 (26.5%), and comedonecrosis in invasive carcinoma in 32 (9.4%) tumors. Solid fields demonstrated either a small nested morphology (n = 50, 14.7%) or medium to large solid fields (n = 61, 18.0%). Cribriform architecture was present in 568 (53.4%) RPs. Medium to large solid fields and comedonecrosis coincided with cribriform architecture in all specimens, and were not observed in cribriform-negative cases. In multivariable analysis adjusted for Prostate-Specific Antigen, pT-stage, GG, surgical margin status and lymph node metastases, cribriform architecture (Hazard Ratio (HR) 9.9; 95% Confidence Interval (CI) 3.9-25.5, P < 0.001) and comedonecrosis (HR 2.1, 95% CI 1.2-3.7, P = 0.01) were independent predictors for metastasis-free survival, while single cells/cords (HR 1.2; 95% CI 0.7-1.8, P = 0.55) and medium to large solid fields (HR 1.6, 95% CI 0.9-2.7, P = 0.09) were not. In conclusion, comedonecrosis in invasive carcinoma is an independent prognostic Gleason 5 pattern for metastasis-free survival after RP. These data support the current recommendations to routinely include cribriform pattern in pathology reports and indicate that comedonecrosis should also be commented on.

Intraductal carcinoma has a minimal impact on Grade Group assignment in prostate cancer biopsy and radical prostatectomy specimens.

AIMS: Intraductal carcinoma (IDC) is an adverse histopathological parameter for prostate cancer outcome, but is not incorporated in current tumour grading. To account for its dismal prognosis and to omit basal cell immunohistochemistry, it has been proposed to grade IDC on the basis of its underlying architectural pattern. The aim of this study was to determine the impact of IDC grade assignment on prostate cancer biopsy and radical prostatectomy tumour grading. METHODS AND RESULTS: A cohort of 1031 prostate cancer biopsies and 835 radical prostatectomies were assigned a Grade Group according to the 2014 International Society of Urological Pathology guidelines, without incorporation of IDC in grading. Tumour grading was compared with a Grade Group in which IDC was graded on the basis of its underlying architecture. Of 1031 biopsies, 139 (13.5%) showed IDC. Grade assignment of IDC led to a Grade Group change in 17 (1.6%) cases: four of 486 (0.8%) Grade Group 1 cases were reclassified as Grade Group 2, nine of 375 (2.4%) Grade Group 2 cases were reclassified as Grade Group 3, and four of 58 (6.9%) Grade Group 4 cases were reclassified as Grade Group 5. IDC was observed in 213 of 835 (25.5%) radical prostatectomies, and its grading led to a change in tumour grade in five of 835 (0.6%) patients, with upgrading in two of 207 (1.0%) patients with Grade Group 1 cancer, in two of 420 (0.5%) patients with Grade Group 2 cancer, and in one of 50 (2%) patients with Grade Group 4 cancer. CONCLUSION: IDC grade assignment led to a Grade Group change in 1.6% of prostate biopsy specimens and in 0.6% of radical prostatectomy specimens. Although the inclusion of IDC in or the exclusion of IDC from the Grade Group might affect decision-making in individual patients, it has a minimal impact on overall prostate cancer management.

Immune response and stromal changes in ductal carcinoma in situ of the breast are subtype dependent.

Ductal carcinoma in situ (DCIS) associated stromal changes and influx of immune cells might be mediators of progression to invasive breast cancer. We studied the interaction between DCIS-associated stromal changes, and immune cell distribution and composition in a well-characterized patient cohort. We included 472 patients with DCIS. The presence of stromal changes, signs of regression, and DCIS-associated immune cell position were determined on hematoxylin and eosin-stained slides. Immune cell composition was characterized by immunohistochemistry (CD4, CD8, CD20, CD68, and FOXP3). The number of intraductal immune cells was quantified per mm2. The interaction between stromal changes, signs of DCIS regression, immune cell composition and location was explored. Stromal changes and signs of DCIS regression were identified in 30 and 7% of the patients, respectively. Intraductal immune cells mainly comprised CD68+ macrophages and CD8+ T cells. Patients with stromal changes had significantly less influx of immune cells within the duct. DCIS regression was associated with an increased number of intraductal FOXP3+ T cells. The highest number of intraductal CD8+ T cells was seen in the ER+ HER2+ subtype. We suggest that DCIS-associated stromal changes prevent the interaction between immune cells and DCIS cells. However, in case of DCIS regression, we surmise a direct interaction between DCIS cells and immune cells, in particular FOXP3+ cells. Furthermore, the increased number of intraductal CD8+ T cells in the ER+ HER2+ DCIS subtype suggests a subtype-specific immune response, which is likely to play a role in the distinct biological behavior of different DCIS subtypes.