W. F. Knox

COX-2 expression is associated with an aggressive phenotype in ductal carcinoma in situ.

Cyclooxygenase type-2 (COX-2) is overexpressed in malignant tumours including breast cancers, though the mechanism of upregulation is unclear. This study aimed to determine COX-2 expression in ductal carcinoma in situ (DCIS) in comparison to invasive breast cancer (IBC) and normal breast, and also to investigate the relationship of COX-2 expression with HER-2 expression, oestrogen receptor (ER), tumour grade and cellular proliferation (Ki67) in DCIS. Cyclooxygenase type-2, HER-2, ER and Ki67 expression were determined by immunohistochemistry on paraffin tissue sections of DCIS (n=187), IBC (n=65) and normal breast reduction tissue (n=60). Cyclooxygenase type-2 expression in DCIS (67%, P<0.001) and IBC (63%, P<0.001) was significantly greater than in normal breast (23%). There was no difference in COX-2 expression level between DCIS and IBC (P=0.87) or between normal breast from reduction mammoplasty tissue and normal breast ducts around DCIS (22%, P=0.29). In DCIS, COX-2 expression was associated with higher cellular proliferation rates (P<0.0001), nuclear grade (P=0.003), with ER negativity (P=0.003) and with HER-2 positivity (P<0.0001). Cyclooxygenase type-2 expression is upregulated in in situ breast cancer and is associated with surrogate markers of an aggressive DCIS phenotype including nonoestrogen-regulated signalling pathways. Cyclooxygenase type-2 inhibition may potentially prevent the development of ER-positive and ER-negative breast cancers.

Survivin expression in in situ and invasive breast cancer relates to COX-2 expression and DCIS recurrence

In lung cancer cyclooxygenase-2 (COX-2) expression has been reported to stabilise survivin, an inhibitor of apoptosis (IAP) which prevents cell death by blocking activated caspases. COX-2 expression limits the ubiquitination of survivin, protecting it from degradation. To determine if COX-2 expression in breast cancer showed an association with survivin expression, we assessed the levels of each protein in ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC); relating expression patterns to recurrence of DCIS after surgery. Patterns of COX-2 and survivin expression were determined by intensity-graded immunohistochemistry of the primary tumours. Patients with DCIS (n=161) which had either recurred (n=47) or shown no evidence of recurrence (n=114) 5 years following primary surgery were studied. These were compared to 58 cases of IBC. Survivin was expressed in the cytoplasm of 59% of DCIS and 17% of IBC. High levels of both cytoplasmic survivin and COX-2 expression significantly correlated to DCIS recurrence. COX-2 expression was present in 72% of DCIS, and levels of expression positively correlated with cytoplasmic survivin expression in DCIS and invasive disease. The majority of DCIS that recurred expressed both proteins (69%) vs 39% nonrecurrent. Recurrence was not seen in DCIS lacking both proteins at 5 years (P=0.001). Expression of the IAP survivin is increased in DCIS and correlates closely with COX-2 expression. Increased expression of IAP, (leading to reduced apoptosis) may explain the effect of COX-2 in increasing recurrence of DCIS after surgical treatment.

Value of the Van Nuys Prognostic Index in prediction of recurrence of ductal carcinoma in situ after breast-conserving surgery

The Van Nuys Prognostic Index (VNPI), an algorithm based on tumour size, tumour grade, presence of necrosis and excision margin width, is claimed to predict local recurrence after breast‐conserving surgery for ductal carcinoma in situ (DCIS). The aim of this study was to examine the validity of the VNPI in a UK population.

The importance of complete excision in the prevention of local recurrence of ductal carcinoma in situ.

Mastectomy probably represents over-treatment for the majority of women with screen detected ductal carcinoma in situ (DCIS) and breast-conserving surgery is now widely advocated. In this study, biopsy cavity shavings were used to ensure complete excision in 129 women undergoing breast-conserving surgery for screen detected DCIS. A margin was considered clear if DCIS was > 1 mm from any margin of excision and shavings were clear. Patients with involved margins (DCIS at resection margin) underwent re-excision, irrespective of shaving status. After re-excision, 101 women (78%) had clear margins and 28 (22%) close margins (DCIS < or = 1 mm from resection margin). Cavity shavings were histologically clear of DCIS in all cases. Ipsilateral DCIS recurrence occurred in 12 (9.3%) patients. Two recurrences also contained invasive carcinoma. The median time to diagnosis was 14 months and all recurrences occurred at the site of the previous biopsy. Seven recurrences were detected at the first annual mammogram, four at the second and one at the third. Ipsilateral recurrence was related to margin status; only 2 out of 101 (2%) patients with clear margins recurred, compared with 10 out of 28 (36%) patients with close margins. Local recurrence and close margin status both correlated with a high modified Van Nuys prognostic index score. Our results indicate that local relapse represents residual DCIS rather than true recurrence in the majority of cases. Cavity shavings have proved ineffective in ensuring complete excision. We now ensure a minimum 10 mm margin of excision around all screen-detected DCIS lesions.

Relationship between hormone receptor status and tumour size, grade and comedo necrosis in ductal carcinoma in situ

Results of the National Surgical Adjuvant Breast Project B‐24 trial indicate that adjuvant tamoxifen therapy is of benefit only in oestrogen receptor (ER)‐ positive ductal carcinoma in situ (DCIS). In the UK, ER status is not routinely determined in DCIS. The aim of this study was to assess the ER status in women with DCIS to determine whether any clinicopathological factors could predict positivity instead of immunohistochemical assessment.

Biological response to hormonal manipulation in oestrogen receptor positive ductal carcinoma in situ of the breast

Adjuvant antioestrogen therapy with tamoxifen is recommended for all women following breast-conserving surgery for ductal carcinoma in situ (DCIS) to reduce local recurrence, despite 50% of lesions being oestrogen receptor (OR) negative. We have investigated the response to hormone manipulation in DCIS by studying changes in epithelial proliferation and progesterone receptor (PR) expression as surrogate molecular markers of treatment effects in DCIS of known OR status. Women were identified who had undergone diagnostic core biopsy followed by surgery for DCIS 14–41 days later. Ki67 (a measure of epithelial cell proliferation) and PR expression were determined by immunohistochemistry on paired paraffin sections of the core biopsy and operative specimens for each patient, with OR and HER-2 measured on the operative specimen. Women were divided into three groups according to whether they had changed hormone therapy (stopped hormone replacement therapy (HRT), group 1), continued taking HRT (group 2) or were not taking HRT (group 3) between core biopsy and surgery. In OR-positive (but not in OR-negative) DCIS after oestrogen withdrawal (group 1), a fall in the mean cell proliferation (P<0.01) was observed. A fall in PR expression between core biopsy and surgery was also seen in this group (P=0.02). No change in either mean cell proliferation or PR expression was seen in the other two groups in OR-positive or -negative DCIS. The fall in proliferation and PR expression occurred regardless of HER-2 status. In conclusion, a biological response to hormone manipulation is only seen in OR-positive DCIS tumours. Any clinical value of antioestrogen therapy is likely to be restricted to this group.

Abstract P3-10-31: Epithelial Proliferation (Ki67) Is Not an Independent Variable for Breast Cancer Relapse in Symptomatic or Screen Detected Breast Cancers (SDBC)

Background: UK screen detected breast cancers (SDBC) (aged 50-65 years) have an overall 97.2% 5 year relative survival compared to 77.6% for symptomatic cancers. Epithelial proliferation has been used to determine therapy in the St. Gallen guidelines (Ki67 ≥30% indicates the need for chemotherapy). Methods: To determine the value of Ki67 in post-menopausal breast cancer in women aged 50-65 years, we have studied Ki67 in 1270 women aged 50-65 years (mean 57 years) with either symptomatic cancers (n=412) or SDBC (n=858) with a 10 year follow up. Results: Ki67 predicted relapse and death in both symptomatic and SDBC. Mode of detection, size, grade, node status and oestrogen receptor (ER) were independently predictive of breast cancer mortality and Ki67 was not an independent variable. In small size ≤15mm ER positive SDBC (n=248) or symptomatic cancers (n=146), Ki67 was not prognostic (p=0.13 and 0.59 respectively). Twelve per cent of symptomatic and 2% of SDBC had died within 5 years. Mean Ki67 in SDBC was 21.4 (SD 10.3) and 34.2 (SD 16.2) in symptomatic cancers (p=≤0.001). ER positive cancers had lower Ki67 levels (p=0.002). For each 10 unit increase in Ki67, increases in distant relapse occurred (RR 1.43:95%CI;1.32-1.55). Ten Year Survival According to Ki67 and Mode of Presentation Discussion: Epithelial proliferation is prognostic in breast cancer but its value is predominantly in large size (≥15mm) symptomatic tumours and Ki67 alone cannot be used to determine therapy. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-31.

Six of the Best, Breast 10

Aims: Stereotactic core biopsy has resulted in an increased preoperative diagnosis of DCIS and has replaced wire-localized open biopsy for screen-detected microcalcification, potentially reducing the need for reoperation to obtain clear excision margins. Our aim was to assess the impact of the introduction of stereotactic core biopsy on the reoperation rate for screen-detected impalpable DCIS. Methods: A retrospective analysis was performed on a cohort of 221 women with screen-detected pure DCIS with (after 1997, n = 74) and without (before 1997, n = 147) a preoperative core biopsy diagnosis. An intraoperative specimen X-ray was performed to assess the adequacy of excision. The two groups of patients were matched for age and DCIS nuclear grade. Results: Pathological and mammographic DCIS tumour sizes were similar (r = 0.71, P < 0.001). Conclusion: Changes from diagnostic to therapeutic primary operative excision for screen-detected DCIS have not resulted in a reduction in the total number of operations required to complete treatment, because mammography underestimates DCIS tumour size in 30 per cent of patients.