Jan P.A. Baak

Microsatellite instability in colorectal cancer

Microsatellite instability (MSI) causes hereditary non‐polyposis colorectal cancer (HNPCC), and occurs in about 15 per cent of sporadic colorectal cancers. Although the basic mechanisms are not clear, there is increased understanding of the clinicopathological consequences of MSI.

Phosphohistone H3 expression has much stronger prognostic value than classical prognosticators in invasive lymph node-negative breast cancer patients less than 55 years of age

The proliferation factor mitotic activity index is the strongest prognostic factor in early breast cancer, but it may lack reproducibility. We analyzed the prognostic value of phosphohistone H3, a marker of cells in late G2 and M phase, measuring highly standardized immunohistochemical nuclear phosphohistone H3 expression by subjective counts and digital image analysis. Expression was compared with classical clinico-pathologic prognostic variables and the mitotic activity index in 119 node-negative invasive breast cancers in patients less than 55 years old treated with adjuvant systemic chemotherapy with long-term follow-up (median 168 months). Nineteen patients (16%) developed distant metastases and 16 (13%) died. Strong phosphohistone H3 expression occurred preferentially in the peripheral growing front; counts were highly reproducible between observers (R=0.92) and highly consistent with digital image analysis (R=0.96). Phosphohistone H3 correlated (P<0.05) with tumor diameter, estrogen receptor, carcinoma grade, and mitotic activity index. Phosphohistone H3 values were systematically (80%) higher than the mitotic activity index. Receiver-operating curve analysis objectively showed that phosphohistone H3 <13 (n=53; 45% of all cases) vs phosphohistone H3≥13 (n=66; 55% of all cases) was the strongest prognostic threshold, with 20-year recurrence-free survival of distant metastases of 96 and 58%, respectively (P=0.0002, HR=9.6). Mitotic activity index was the second strongest prognostic variable (P=0.003, HR=3.9). In multivariate analysis, phosphohistone H3 <13 vs≥13 exceeded the prognostic value of the mitotic activity index. None of the other classical prognostic factors examined offered prognostic value additional to phosphohistone H3. Phosphohistone H3 is by far the strongest prognostic variable in early invasive node-negative breast cancer patients less than 55 years old with long-term follow-up.

Biologic profiling of lymph node negative breast cancers by means of microRNA expression.

Breast cancer is a heterogeneous disease. Different subgroups can be recognized on the basis of the steroid receptors, HER-2, cytokeratin expression and proliferation patterns. As a result of mRNA-profiling studies, five major groups can be recognized, of which the triple-negative and basal-like tumors have the worst prognosis. Many of these tumors have a high proliferation that has the strongest prognostic value in node negative breast cancer. In the current study we analyzed the microRNA pattern in 103 lymph node negative breast cancers and compared these profiles with different biological characteristics and clinicopathological features. Unsupervised hierarchical cluster analysis divides the patients into four main groups, of which the basal-like/triple-negative group is the most prominent (11% of all cases), the luminal A cancers containing the Her2 negative and estrogen receptor/progesterone receptor-positive tumors is the largest group (57%), and the group of luminal B (32%) is more heterogeneous and contains the Her2 positive/estrogen receptor-negative patients as well. The highest overall classification values by analysis of variance followed by cross validation (leave one sample out and reselect genes) were found for cytokeratin 5 and 6, triple-negative and estrogen receptor, with 97, 90 and 90% accuracy, respectively. MiR-106b gene is prominent in all of these signatures and correlates strongest with high proliferation. Other interesting observations are the presence of several microRNAs (miR532-5p, miR-500, miR362-5p, and miR502-3p) located at Xp11.23 in cancers with a triple-negative signature, and the upregulation of several miR-17 cluster members in estrogen receptor-negative tumors. The current study shows that estrogen receptor negativity and cytokeratin 5 and 6 expression are important, and specific biological processes in lymph node negative breast cancer, as microRNA signatures are strongest in these subgroups.

Local immune response in the microenvironment of CIN2-3 with and without spontaneous regression

Fifteen to thirty percent of cases with histologically confirmed CIN2–3 in cervical biopsies regress spontaneously (ie, show CIN1 or less in the follow-up cervical cone). The balance between immune-reactive cells from the host and high-risk human papillomavirus (hrHPV) genotypes may provide a biological explanation for this phenomenon. We retrospectively studied 55 cases of CIN2–3 in a cervical biopsy with subsequent cervical cone to assess whether hrHPV genotypes (by AMPLICOR and Linear Array tests) CD4, CD8, CD25, CD138 and Foxp3 cells (by quantitative immunohistochemistry) in the cervical biopsies can predict regression (defined as CIN1 or less in the follow-up cone biopsy). Eighteen percent of the CIN2–3 cases regressed (median biopsy–cervical cone time interval: 12.0 weeks, range: 5.0–34.1 weeks). HPV-16 correlated with low CD8+ and high CD25+. None of the regressing CIN2–3 lesions contained HPV-16. The regressing CIN2–3 lesions had lower numbers of stromal CD138+ and higher numbers of stromal CD8+cells; higher stromal and intra-epithelial ratios of CD4+/CD25+ cells; higher ratios of CD8+/CD25+ cells and lower ratios of CD8+/CD4+, CD138+/Foxp3+ and CD25+/Foxp3+cells in the stroma. With multivariate survival analysis, stromal CD8+ cell numbers, CD4+/CD25+ cell ratios and CD138+ cell numbers are found to be independent regression predictors. In conclusion, in non-HPV-16 CIN2–3 lesions, assessing stromal immune cells can be a useful prognostic indicator of regression or persistence.

Comparison of different commercial methods for HPV detection in follow-up cytology after ASCUS/LSIL, prediction of CIN2-3 in follow up biopsies and spontaneous regression of CIN2-3

OBJECTIVE Different Human Papilloma Virus (HPV) tests are currently used. An integrated comparison of the Amplicor, Cobas4800, PreTect HPV-Proofer and APTIMA HPV tests has not been done. METHODS We compared the high-risk HPV detection power of these HPV tests in 528 consecutive population-based follow-up Liquid-Based Cytology samples (LBC) after ASCUS/LSIL index cytology. Their sensitivity and specificity to detect HPV in LBC, their predictive values of histopathologic CIN2-3 in follow-up punch biopsies and CIN2-3 regression in the subsequent cones was assessed. The HPV subtypes detected by the Linear Array genotyping-test (LA), PreTect HPV-Proofer and Cobas4800 were also compared. The follow-up histopathology was consensus expert-reviewed and Ki67/p16-supported. The predictive values of the HPV results in LBC by the different tests for presence of CIN2-3 in follow-up biopsies, and regression in subsequent cones, was assessed. RESULTS Amplicor, Cobas4800 and APTIMA show good agreement for HPV-positivity/negativity. PreTect HPV-Proofer has many discrepancies versus any of the other methods. The sensitivities for Amplicor, Cobas4800 and APTIMA to detect CIN2-3 were very high (96-100%), but rather low for PreTect HPV-Proofer (53%). Specificity in case of CIN1 or less in follow-up biopsies of Amplicor and Cobas4800 is lower than APTIMA and highest for PreTect HPV-Proofer. HPV subtyping by LA agreed in 90% with Cobas4800 but 70% with PreTect HPV-Proofer. CONCLUSIONS The Amplicor, Cobas4800 and APTIMA give comparable results but PreTect HPV-Proofer differs from the other tests, with low sensitivity but higher specificity. None of the methods predicted regression of CIN2-3.

Microsatellite instability and DNA ploidy in colorectal cancerx: Potential implications for patients undergoing systematic surveillance after resection

Appropriate stratification tools for targeted surveillance after resection for colorectal cancer (CRC) are lacking. The objective of the current study was to investigate the effect of microsatellite instability (MSI) and DNA ploidy on surveillance after surgery.

The impact of epithelial biomarkers, local immune response and human papillomavirus genotype in the regression of cervical intraepithelial neoplasia grades 2-3.

Background and aims 15–30% of cases of cervical intraepithelial neoplasia grades 2–3 (CIN2–3) detected in punch biopsies regress spontaneously (ie, show CIN1 or less in the follow-up cone). Epithelial retinoblastoma protein (pRb), tumour suppressor protein (p53), HPV genotype and immunoreactive cells have been reported to be helpful in predicting regression but their interaction in regression prediction is unknown. Material and methods 55 cases of CIN2–3 in cervical biopsies with subsequent cervical cones were studied retrospectively to assess how epithelial biomarkers, immunoreactive cells (with immunohistochemistry) and high-risk (hr) HPV genotypes (by the AMPLICOR and linear array tests) prognostically interact with epithelial pRb and p53. Results 18% of CIN2–3s regressed (median biopsy–cone interval of 12.0 weeks, range 5.0–34.1 weeks). CIN2–3s that regressed had higher epithelial pRb and p53, lower stromal CD25+ and CD138+, and higher CD8 cells than persistent lesions. They also had higher ratios of CD4+/CD25+ and CD8+/CD25 in stroma and epithelium. HPV16 correlated with low pRb and low CD8+. With multivariate analysis a combined high ratio of CD8+/CD25+ in the stroma, high epithelial pRb and p53 expression had independent value to predict the regression. Conclusions CIN2–3 lesions with a non-hrHPV16 infection, high ratios of stromal CD8+/CD25+ and high epithelial expression of pRb or p53 are associated with spontaneous regression.

Squamous morules are functionally inert elements of premalignant endometrial neoplasia

Squamous morules are a common component of premalignant glandular lesions that are followed by glandular, rather than squamous, carcinomas. We tested the hypothesis that the appearance of glands associated with morules predicts cancer risk, and undertook molecular testing to determine the clonal and hormonal response properties of admixed squamous and glandular elements. A total of 66 patients with squamous morules in an index endometrial biopsy had follow-up clinical data (average follow-up: interval 31 months, 2.5 biopsies) showing development of carcinoma in 11% (7/66) of cases. The histological appearance of morule-associated glands in the index biopsy was significantly associated with this clinical outcome, with the majority (71%, 5/7) of cancer occurrences following an overtly premalignant lesion (endometrial intraepithelial neoplasia) with squamous morules. Eight endometrial intraepithelial neoplasias with squamous morules were examined by immunohistochemistry for estrogen and progesterone receptors and mitotic activity (Ki-67 antigen percent stained). Glandular components had abundant estrogen and progesterone receptors, and high levels of mitotic activity in all cases. In sharp contrast, all squamous morules were devoid of sex hormone receptors and had undetectable or extremely low-proliferation rates. When mutated, the same specific PTEN mutation was detected in squamous and glandular elements, indicating that both are of common lineage. The clinical and laboratory data are consistent with a model of morule biology in which squamous morules are a hormonally incompetent subpopulation of endometrial glandular lesions. Isolated morules might result from artifactual displacement from their native glandular context, or selective hormonally induced regression of the glandular but not squamous components over time. Subsequent cancer risk, as promoted by estrogens, is greatest when the glandular component has the appearance of endometrial intraepithelial neoplasia. Even isolated morules should be carefully followed, however, to exclude a coexisting undersampled, or occult, glandular lesion.

LOH at 1p31 (ARHI) and proliferation in lymph node-negative breast cancer.

Background: The mitotic activity index (MAI) is a strong prognosticator in node-negative invasive breast cancer patients. Recently, a correlation between the MAI and specific chromosomal aberrations at chromosome 1p was described. Methods: Analysis of MAI, immunohistochemical staining patterns for proliferation-associated phosphohistone H3 (PPH3), phosphorylated ERK1/2, p21, cyclin E, Ki67 and cyclin D1 proteins; and prognosis in 158 adjuvant chemotherapy-treated T1-2N0M0 invasive breast cancer patients, analysis of LOH at 1p31 (including ARHI) using the dinucleotide repeats D1S207, D1S430 and D1S464 in 76 patients. Single and multivariate survival analysis was used to evaluate the importance of the various markers tested. Results: LOH at 1p31 did not correlate with MAI nor provide prognostic information. Phosphohistone H3 was the best prognosticator for patients in all age groups with 20 year distant metastasis free survival of distant metastases 93% vs. 72% respectively (p = 0.004, HR = 4.5). In multivariate analysis, phosphohistone H3 < 13 vs. ≥13 exceeded the prognostic value of the mitotic activity index. Conclusions: LOH at 1p31 is common in breast cancer, and correlates with loss of proliferation-associated proteins, but not with MAI, PPH3 or prognosis. PPH3 is the best prognosticator in this study group of adjuvant chemotherapy-treated lymph node-negative breast cancer patients.

Emerging concepts of apolipoprotein D with possible implications for breast cancer

Apolipoprotein D (ApoD) is a small glycoprotein of 24 kD, and a member of the lipocalin family. ApoD exerts several intracellular mechanistic roles, especially ligand binding. Some putative ligands are arachidonic acid, progesterone, and tamoxifen. It probably has a binding/reservoir function of these ligands in the cytoplasm. Furthermore, ApoD has features compatible with endosomal trafficking, proteolytic activity and interactions in cellular signal pathways. ApoD inhibits translocation of phosphorylated MAPK into the nucleus. Moreover, ApoD is associated with reduced proliferative activity of cancer cells, and is abundantly raised in senescent cells. In breast cancer, ApoD expression is associated with favourable histology and clinical stage, whereas in adjacent tumour stroma ApoD expression is a marker of adverse prognosis. Oestrogen receptor expression in breast cancer is inversely related to ApoD expression. Therefore, a combined oestrogen receptor positivity/ApoD positivity, could reflect a non-functional oestrogen receptor pathway, and this subset of breast cancer patients does not react to adjuvant tamoxifen treatment. The triangular relationship between oestrogen receptor, tamoxifen and ApoD should be further explored.