Evaluation of applying IHC4 as a prognostic model in the translational study of Intergroup Exemestane Study (IES): PathIES

BACKGROUND

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. This PathIES aimed to assess the role of immunohistochemical (IHC)4 score in determining the relative sensitivity to either tamoxifen or sequential treatment with tamoxifen and exemestane.

PATIENTS AND METHODS

Primary tumour samples were available for 1274 patients (27% of IES population). Only patients for whom the IHC4 score could be calculated (based on oestrogen receptor, progesterone receptor, HER2 and Ki67) were included in this analysis (N = 430 patients). The clinical score (C) was based on age, grade, tumour size and nodal status. The association of clinicopathological parameters, IHC4(+C) scores and treatment effect with time to distant recurrence-free survival (TTDR) was assessed in univariable and multivariable Cox regression analyses. A modified clinical score (PathIEscore) (N = 350) was also estimated.

RESULTS

Our results confirm the prognostic importance of the original IHC4, alone and in conjunction with clinical scores, but no significant difference with treatment effects was observed. The combined IHC4 + Clinical PathIES score was prognostic for TTDR (P < 0.001) with a hazard ratio (HR) of 5.54 (95% CI 1.29-23.70) for a change from 1st quartile (Q1) to Q1-Q3 and HR of 15.54 (95% CI 3.70-65.24) for a change from Q1 to Q4.

CONCLUSION

In the PathIES population, the IHC4 score is useful in predicting long-term relapse in patients who remain disease-free after 2-3 years. This is a first trial to suggest the extending use of IHC4+C score for prognostic indication for patients who have switched endocrine therapies at 2-3 years and who remain disease-free after 2-3 years.

Metallothionein in human gastrointestinal cancer

Metallothionein (MT) is a small thiol-rich metalloprotein with antioxidant properties, involved in tumour pathophysiology and therapy resistance. In order to assess the contribution of MT in gastrointestinal carcinogenesis, this study examined both the MT content by radioimmunoassay and the MT localization by immunohistochemistry in pairs of neoplastic and normal-appearing human gastrointestinal tissues. In addition, the relationship between MT expression and major clinicopathological parameters was assessed. The MT concentration of gastric carcinomas and of colorectal adenomas, carcinomas, and liver metastases was found to be significantly lower than that of corresponding normal-appearing tissue. A relatively high MT content, however, was found to be associated with the villous character of colorectal adenomas and with the Dukes' stage of colorectal carcinomas, indicating a relationship between MT level and malignant potential. Immunohistochemical evaluation showed a fairly good correlation with these quantitative data. MT was found to be expressed at a low level and in a patchy pattern in the gastrointestinal neoplastic and metastatic tissues, whereas in normal-appearing gastrointestinal mucosa MT was uniformly distributed in the cytoplasm and/or nucleus of apical cells. Although in the gastric cancer patients no association was found between the MT concentration and the clinicopathological parameters, the strong MT expression in areas with intestinal metaplasia, known to have neoplastic potential, further points to a relationship between this antioxidant metalloprotein and the malignant character of cells. Gastrointestinal neoplasms are apparently accompanied by a low level and decreased expression of MT, but those with a relatively high level seem to have an increased malignant potential. Further studies will be required to determine the clinical relevance of these observations.

European trials with total mesorectal excision

The outcome after surgery for rectal cancer differs markedly between patient series regarding local recurrence rates and survival. A high incidence of local recurrence is associated with conventional, nonstandardized procedures. To improve results of surgery, various additional treatments, such as radiotherapy, chemotherapy, and immunotherapy, have been tested. The Swedish Rectal Cancer Trial (SRCT) was the first trial to show that better local control achieved with preoperative radiotherapy resulted in improved survival. In recent years local control and survival have been further improved by the introduction of standardized total mesorectal excision (TME) surgery. A major problem of published studies on adjuvant therapy is that surgery was not standardized in these studies. Furthermore, quality control of the surgical technique by standardized pathological examination of the specimen is absent in most studies. In Europe, TME has become the preferred standard of operative management for rectal cancer. Adjuvant therapy studies should now be reexamined based on a platform of standardized, optimal surgery and pathology. We studied the European trials in which TME surgery is intentionally performed. Most of these trials are still in progress, with follow-up too short for definitive results, apart from interim analyses. However, the Dutch TME trial has already shown that performing a large, multicenter trial with quality control of both surgery and pathology is feasible.

Metallothionein in human gastrointestinal cancer

Metallothionein (MT) is a small thiol-rich metalloprotein with antioxidant properties, involved in tumour pathophysiology and therapy resistance. In order to assess the contribution of MT in gastrointestinal carcinogenesis, this study examined both the MT content by radioimmunoassay and the MT localization by immunohistochemistry in pairs of neoplastic and normal-appearing human gastrointestinal tissues. In addition, the relationship between MT expression and major clinicopathological parameters was assessed. The MT concentration of gastric carcinomas and of colorectal adenomas, carcinomas, and liver metastases was found to be significantly lower than that of corresponding normal-appearing tissue. A relatively high MT content, however, was found to be associated with the villous character of colorectal adenomas and with the Dukes' stage of colorectal carcinomas, indicating a relationship between MT level and malignant potential. Immunohistochemical evaluation showed a fairly good correlation with these quantitative data. MT was found to be expressed at a low level and in a patchy pattern in the gastrointestinal neoplastic and metastatic tissues, whereas in normal-appearing gastrointestinal mucosa MT was uniformly distributed in the cytoplasm and/or nucleus of apical cells. Although in the gastric cancer patients no association was found between the MT concentration and the clinicopathological parameters, the strong MT expression in areas with intestinal metaplasia, known to have neoplastic potential, further points to a relationship between this antioxidant metalloprotein and the malignant character of cells. Gastrointestinal neoplasms are apparently accompanied by a low level and decreased expression of MT, but those with a relatively high level seem to have an increased malignant potential. Further studies will be required to determine the clinical relevance of these observations.

Prognostic value of DNA cytometry in 281 premenopausal patients with lymph node negative breast carcinoma randomized in a control trial: multivariate analysis with Ki-67 index, mitotic count, and microvessel density

BACKGROUND

The clinical relevance of DNA image cytometry (ICM) and flow cytometry (FCM) remains under investigation in breast carcinoma. The objective of the current work was to study the prognostic value of DNA ICM and FCM in a series of patients randomized in a control trial. A multivariate analysis has been performed including other factors still under investigation such as Ki-67 index, mitotic count, microvessel density, and P53 and Bcl-2 expression.

METHODS

Two hundred and eighty-one patients were randomized in the European Organization for Research and Treatment of Cancer 10854 trial comparing surgery followed by one course of perioperative chemotherapy versus surgery alone. Tumor parameters studied were pT, multicentricity, tumor grading according to modified Scarff-Bloom-Richardson, estrogen receptors, mitotic count per 1.7 mm(2), MIB-1, and BCL-2 scores, microvessel density, and p53 expression. ICM DNA parameters studied from paraffin embedded specimens, were DNA ploidy, proliferative index, 2c deviation index, malignancy grade, and Auer-Baldetorp typing. FCM DNA parameters analyzed on the same samples were ploidy and S-phase fraction statistics. The influence of tumor parameters, and DNA parameters on overall survival (OS), disease free survival (DFS), and metastasis-free survival (MFS) was evaluated using the Cox model. Median follow-up was 82 months.

RESULTS

For OS, the prognostic parameters retained were pathologic tumor size (pT) and mitotic index (MI). Overall survival was 94% and 68% for tumors pT1/MI less than 10 and pT2-3 MI greater than or equal to 10, respectively. For DFS, age, multicentricity, and grading according to modified Scarff and Bloom were predicting factors with the same relative risk. Disease free survival was 96%, 78% and 68% respectively, when 1, 2, or 3 of those factors were present. For MFS, the only retained predicting factor was MI. MFS was 97% and 73% when MI was less than 10 and MI was greater than or equal to 10, respectively.

CONCLUSIONS

Evaluation of proliferative compartment was the most important predicting factor for OS and MFS in the current series of premenopausal lymph node negative patients with breast invasive carcinoma. When working on paraffin embedded tissue, the best way of assessing it was MI count. ICM DNA analysis results were not selected in multivariate analysis. DNA analysis by FCM should be considered as an unsuitable technique when working on paraffin embedded tissue.