Breast-Conserving Surgery with or without Irradiation in Early Breast Cancer.

BACKGROUND: Limited level 1 evidence is available on the omission of radiotherapy after breast-conserving surgery in older women with hormone receptor-positive early breast cancer receiving adjuvant endocrine therapy. METHODS: We performed a phase 3 randomized trial of the omission of irradiation; the trial population included women 65 years of age or older who had hormone receptor-positive, node-negative, T1 or T2 primary breast cancer (with tumors ≤3 cm in the largest dimension) treated with breast-conserving surgery with clear excision margins and adjuvant endocrine therapy. Patients were randomly assigned to receive whole-breast irradiation (40 to 50 Gy) or no irradiation. The primary end point was local breast cancer recurrence. Regional recurrence, breast cancer-specific survival, distant recurrence as the first event, and overall survival were also assessed. RESULTS: A total of 1326 women were enrolled; 658 were randomly assigned to receive whole-breast irradiation and 668 to receive no irradiation. The median follow-up was 9.1 years. The cumulative incidence of local breast cancer recurrence within 10 years was 9.5% (95% confidence interval [CI], 6.8 to 12.3) in the no-radiotherapy group and 0.9% (95% CI, 0.1 to 1.7) in the radiotherapy group (hazard ratio, 10.4; 95% CI, 4.1 to 26.1; P<0.001). Although local recurrence was more common in the group that did not receive radiotherapy, the 10-year incidence of distant recurrence as the first event was not higher in the no-radiotherapy group than in the radiotherapy group, at 1.6% (95% CI, 0.4 to 2.8) and 3.0% (95% CI, 1.4 to 4.5), respectively. Overall survival at 10 years was almost identical in the two groups, at 80.8% (95% CI, 77.2 to 84.3) with no radiotherapy and 80.7% (95% CI, 76.9 to 84.3) with radiotherapy. The incidence of regional recurrence and breast cancer-specific survival also did not differ substantially between the two groups. CONCLUSIONS: Omission of radiotherapy was associated with an increased incidence of local recurrence but had no detrimental effect on distant recurrence as the first event or overall survival among women 65 years of age or older with low-risk, hormone receptor-positive early breast cancer. (Funded by the Chief Scientist Office of the Scottish Government and the Breast Cancer Institute, Western General Hospital, Edinburgh; ISRCTN number, ISRCTN95889329.).

Breast-conserving surgery with or without irradiation in women aged 65 years or older with early breast cancer (PRIME II): a randomised controlled trial.

BACKGROUND: For most older women with early breast cancer, standard treatment after breast-conserving surgery is adjuvant whole-breast radiotherapy and adjuvant endocrine treatment. We aimed to assess the effect omission of whole-breast radiotherapy would have on local control in older women at low risk of local recurrence at 5 years. METHODS: Between April 16, 2003, and Dec 22, 2009, 1326 women aged 65 years or older with early breast cancer judged low-risk (ie, hormone receptor-positive, axillary node-negative, T1-T2 up to 3 cm at the longest dimension, and clear margins; grade 3 tumour histology or lymphovascular invasion, but not both, were permitted), who had had breast-conserving surgery and were receiving adjuvant endocrine treatment, were recruited into a phase 3 randomised controlled trial at 76 centres in four countries. Eligible patients were randomly assigned to either whole-breast radiotherapy (40-50 Gy in 15-25 fractions) or no radiotherapy by computer-generated permuted block randomisation, stratified by centre, with a block size of four. The primary endpoint was ipsilateral breast tumour recurrence. Follow-up continues and will end at the 10-year anniversary of the last randomised patient. Analyses were done by intention to treat. The trial is registered on ISRCTN.com, number ISRCTN95889329. FINDINGS: 658 women who had undergone breast-conserving surgery and who were receiving adjuvant endocrine treatment were randomly assigned to receive whole-breast irradiation and 668 were allocated to no further treatment. After median follow-up of 5 years (IQR 3·84-6·05), ipsilateral breast tumour recurrence was 1·3% (95% CI 0·2-2·3; n=5) in women assigned to whole-breast radiotherapy and 4·1% (2·4-5·7; n=26) in those assigned no radiotherapy (p=0·0002). Compared with women allocated to whole-breast radiotherapy, the univariate hazard ratio for ipsilateral breast tumour recurrence in women assigned to no radiotherapy was 5·19 (95% CI 1·99-13·52; p=0·0007). No differences in regional recurrence, distant metastases, contralateral breast cancers, or new breast cancers were noted between groups. 5-year overall survival was 93·9% (95% CI 91·8-96·0) in both groups (p=0·34). 89 women died; eight of 49 patients allocated to no radiotherapy and four of 40 assigned to radiotherapy died from breast cancer. INTERPRETATION: Postoperative whole-breast radiotherapy after breast-conserving surgery and adjuvant endocrine treatment resulted in a significant but modest reduction in local recurrence for women aged 65 years or older with early breast cancer 5 years after randomisation. However, the 5-year rate of ipsilateral breast tumour recurrence is probably low enough for omission of radiotherapy to be considered for some patients. FUNDING: Chief Scientist Office (Scottish Government), Breast Cancer Institute (Western General Hospital, Edinburgh).

Proximity ligation assays for isoform-specific Akt activation in breast cancer identify activated Akt1 as a driver of progression.

The PI3K/Akt signal transduction pathway plays an important role in cancer progression and cell survival. Akt activation is associated with poor outcome in endocrine-treated breast cancer, whereas high levels of cytoplasmic Akt2 are associated with an improved overall survival. Proximity ligation assays (PLAs) were used to determine quantitative expression levels of isoform-specific activation (phosphorylation) of Akt1 and Akt2 in formalin-fixed, paraffin-embedded cell lines and breast cancer tumour tissues in situ. PLAs demonstrated a range of expression in breast cancer samples for total pAkt1 and pAkt2. High levels of pAkt1 were associated with reduced DRFS (HR: 1.45, 95% CI 1.14-1.83, p = 0.002) and OS (HR: 1.42, 95% CI 1.10-1.83, p = 0.007). When PLA results were combined, patients that had high levels of pAkt1 only had a significantly decreased DRFS (HR: 1.92, 95% CI 1.34-2.76, p = 0.005) and OS (HR: 1.94, 95% CI 1.32-2.86, p = 0.008) compared to other patients. Using PLAs to discriminate activation of Akt1 versus Akt2 suggests that Akt1 drives progression in early breast cancers. In cases where both Akt1/Akt2 are activated, Akt2 may act to reverse this effect. Using PLAs, we have measured activation of Akt1 and Akt2 proteins separately in situ in FFPE breast cancer samples.

The p160 ER co-regulators predict outcome in ER negative breast cancer.

The SRC family of ER co-regulators are frequently overexpressed in breast cancer. Overexpression of AIB1 appears to be linked to hormone resistance in HER2 positive breast cancer. However, the role of these co-regulators in ER negative disease is poorly understood. SRC1, SRC2 and AIB1 expression was determined by immunohistochemical analysis of tissue microarrays constructed from tumours within the Edinburgh Breast Conservation Series (BCS). The BCS represents a fully documented consecutive cohort of 1,812 patients treated by breast conservation surgery in a single institution. Our results demonstrate tumours that overexpress both HER2 and AIB1 were associated with markedly reduced relapse free, distant relapse free and overall survival compared to HER2 and AIB1 only overexpressing tumours irrespective of ER status. In ER negative disease both SRC1 and AIB1 were linked to early relapse and death. The SRC family of ER co-regulators is involved in early relapse and resistance in both ER negative and ER positive breast cancer challenging the conventional concept that this effect is mediated solely via the ER.

Expression of activated type I receptor tyrosine kinases in early breast cancer.

Overexpression of EGFR, HER2 and HER3 are known to be associated with poor outcome in breast cancer. Few studies have examined the clinical impact of activation of these proteins. In the present study, we evaluated EGFR, HER2 and HER3 and the activated (phosphorylated) forms of these proteins in patients with early breast cancer. EGFR, HER2, HER3, pEGFR, pHER2 and pHER3 expression was determined by immunohistochemical analysis of tissue microarrays constructed from tumours within the Edinburgh Breast Conservation Series (BCS). The BCS represents a fully-documented consecutive cohort of 1,812 patients treated by breast conservation surgery in a single institution. Our results demonstrate overexpression of HER2 and pHER2 to be associated with a significant reduction in overall survival (OS) (HR: 1.66, 95 % CI 1.22-2.26, p = 0.001 and HR: 1.57, 95 % CI 1.22-2.03, p = 0.001, respectively) and distant relapse-free survival (DRFS) (HR: 1.63, 95 % CI 1.23-2.18, p = 0.001 and HR: 1.55, 95 % CI 1.23-1.97, p = 0.0002, respectively). Paradoxically, expression of pEGFR was associated with a significantly improved OS (HR: 0.67 95 % CI 0.50-0.91, p = 0.01) and DRFS (HR: 0.73, 95 % CI 0.56-0.96, p = 0.025). Expression of activated EGFR/HER2 provides additional information on ER positive breast cancer patients and suggests alternative treatment for those in this subgroup.

Histological grading of invasive breast carcinoma--a simplification of existing methods in a large conservation series with long-term follow-up.

AIMS: To assess the validity of grading in the Edinburgh Breast Conservation Series; a consecutive cohort of 1812 early breast cancer patients treated by breast conservation and radiotherapy between 1981 and 1998 in a single specialist centre with > or =9 years' follow-up and full staging data. METHODS AND RESULTS: A single pathologist (J.St.J.T) graded 1650 cases using the Elston and Ellis method (EE) with particular reference to the component data: acinar differentiation, nuclear pleomorphism and mitotic counts. The original method was then compared with binary scoring of the same components and the relationship to prognosis reassessed. EE grades and individual grade components were prognostic (P < 0.0001) with 10-year cause-specific survival of 95.6%, 86.4% and 74.7% for EE grades 1, 2 and 3, respectively. A binary scoring of grade components produces four groups, splitting EE grade 2 tumours into two groups with different outcomes--10-year survival rates for the four revised grades were 96.0%, 89.0%, 79.7% and 75.4%, respectively. CONCLUSIONS: Existing grading methodology is fully applicable in the narrower context of a conservation series but can be simplified. Subdivision of EE grade 2 into a true intermediate prognosis group and a second group with a worse prognosis also adds benefit.

Impact of screening and risk factors for local recurrence and survival after conservative surgery and radiotherapy for early breast cancer: results from a large series with long-term follow-up.

PURPOSE: To investigate conventional prognostic factors for ipsilateral breast tumor recurrence (IBTR), distant metastasis (DM), and survival after breast-conserving therapy (BCT) in screen-detected and symptomatic cases on surveillance up to 25 years. PATIENTS AND METHODS: A total of 1812 consecutive patients in three cohorts (1981-1989, 1990-1992, and 1993-1998) with T12N01M0 invasive breast cancer were treated with BCT (median follow-up, 14 years). Tumor type and grade were reviewed by a single pathologist. Hormone receptor status was measured by immunohistochemistry on tissue microarrays. A Cox proportional hazards model was used to assess independent prognostic variables for relapse and survival. RESULTS: A total of 205 IBTR occurred, with 5-, 10-, 15-, and 20-year actuarial relapse rates of 4.5% (95% confidence interval [CI] 3.35-5.5%), 8.4% (95% CI 7.1-9.8%), 14.1% (95% CI 12.0-16%), and 17.4% (95% CI 14.5-20.2%). Number of nodes, young age, pathologic tumor size, and multifocality were significant factors for IBTR. Three hundred seventy-eight patients developed DM. The actuarial metastatic rate was 12% at 5 years and 17.9% at 10 years. Young age, number of positive nodes, pathologic tumor size, and tumor grade were significant factors for DM relapse. When conventional prognostic indices were taken into account screen-detected cancers showed no improvement in overall relapse or survival rate compared with symptomatic cases but did show a reduced risk of DM after IBTR. After 10 years IBTR relapse continued at a constant rate of 0.87% per annum. CONCLUSIONS: The Edinburgh BCT series has shown that screen-detected invasive breast cancers do not have significantly different clinical outcomes compared with symptomatic cases when pathologic risk factors are taken into account. This suggests that these patients be managed in a similar way.