Simple versus radical mastectomy. Preliminary report of the Cardiff breast trial

Axillary treatment for operable primary breast cancer

BACKGROUND

Axillary surgery is an established part of the management of primary breast cancer. It provides staging information to guide adjuvant therapy and potentially local control of axillary disease. Several alternative approaches to axillary surgery are available, most of which aim to spare a proportion of women the morbidity of complete axillary dissection.

OBJECTIVES

To assess the benefits and harms of alternative approaches to axillary surgery (including omitting such surgery altogether) in terms of overall survival; local, regional and distant recurrences; and adverse events.

SEARCH METHODS

We searched the Cochrane Breast Cancer Group Specialised Register, MEDLINE, Pre-MEDLINE, Embase, CENTRAL, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov on 12 March 2015 without language restrictions. We also contacted study authors and checked reference lists.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including women with clinically defined operable primary breast cancer conducted to compare axillary lymph node dissection (ALND) with no axillary surgery, axillary sampling or sentinel lymph node biopsy (SLNB); RCTs comparing axillary sampling with SLNB or no axillary surgery; RCTs comparing SLNB with no axillary surgery; and RCTs comparing ALND with or without radiotherapy (RT) versus RT alone.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each potentially relevant trial for inclusion. We independently extracted outcome data, risk of bias information and study characteristics from all included trials. We pooled data according to trial interventions, and we used hazard ratios (HRs) for time-to-event outcomes and odds ratios (OR) for binary outcomes.

MAIN RESULTS

We included 26 RCTs in this review. Studies were at low or unclear risk of selection bias. Blinding was not done, but this was only considered a source of bias for outcomes with potential for subjectivity in measurements. We found no RCTs of axillary sampling versus SLNB, axillary sampling versus no axillary surgery or SLNB versus no axillary surgery. No axillary surgery versus ALND Ten trials involving 3849 participants compared no axillary surgery versus ALND. Moderate quality evidence showed no important differences between overall survival of women in the two groups (HR 1.06, 95% confidence interval (CI) 0.96 to 1.17; 3849 participants; 10 studies) although no axillary surgery increased the risk of locoregional recurrence (HR ranging from 1.10 to 3.06; 20,863 person-years of follow-up; four studies). It was uncertain whether no surgery increased the risk of distant metastasis compared with ALND (HR 1.06, 95% CI 0.87 to 1.30; 946 participants; two studies). Low-quality evidence indicated no axillary surgery decreased the risk of lymphoedema compared with ALND (OR 0.31, 95% CI 0.23 to 0.43; 1714 participants; four studies). Axillary sampling versus ALND Six trials involving 1559 participants compared axillary sampling versus ALND. Low-quality evidence indicated similar effectiveness of axillary sampling compared with ALND in terms of overall survival (HR 0.94, 95% CI 0.73 to 1.21; 967 participants; three studies) but it was unclear whether axillary sampling led to increased risk of local recurrence compared with ALND (HR 1.41, 95% CI 0.94 to 2.12; 1404 participants; three studies). The relative effectiveness of axillary sampling and ALND for locoregional recurrence (HR 0.74, 95% CI 0.46 to 1.20; 406 participants; one study) and distant metastasis was uncertain (HR 1.05, 95% CI 0.74 to 1.49; 406 participants; one study). Lymphoedema was less likely after axillary sampling than after ALND (OR 0.32, 95% CI 0.13 to 0.81; 80 participants; one study). SLNB versus ALND Seven trials involving 9426 participants compared SLNB with ALND. Moderate-quality evidence showed similar overall survival following SLNB compared with ALND (HR 1.05, 95% CI 0.89 to 1.25; 6352 participants; three studies; moderate-quality evidence). Differences in local recurrence (HR 0.94, 95% CI 0.24 to 3.77; 516 participants; one study), locoregional recurrence (HR 0.96, 95% CI 0.74 to 1.24; 5611 participants; one study) and distant metastasis (HR 0.80, 95% CI 0.42 to 1.53; 516 participants; one study) were uncertain. However, studies showed little absolute difference in the aforementioned outcomes. Lymphoedema was less likely after SLNB than ALND (OR ranged from 0.04 to 0.60; three studies; 1965 participants; low-quality evidence). Three studies including 1755 participants reported quality of life: Investigators in two studies found quality of life better after SLNB than ALND, and in the other study observed no difference. RT versus ALND Four trials involving 2585 participants compared RT alone with ALND (with or without RT). High-quality evidence indicated that overall survival was reduced among women treated with radiotherapy alone compared with those treated with ALND (HR 1.10, 95% CI 1.00 to 1.21; 2469 participants; four studies), and local recurrence was less likely in women treated with radiotherapy than in those treated with ALND (HR 0.80, 95% CI 0.64 to 0.99; 22,256 person-years of follow-up; four studies). Risk of distant metastasis was similar for radiotherapy alone as for ALND (HR 1.07, 95% CI 0.93 to 1.25; 1313 participants; one study), and whether lymphoedema was less likely after RT alone than ALND remained uncertain (OR 0.47, 95% CI 0.16 to 1.44; 200 participants; one study). Less surgery versus ALND When combining results from all trials, treatment involving less surgery was associated with reduced overall survival compared with ALND (HR 1.08, 95% CI 1.01 to 1.17; 6478 participants; 18 studies). Whether local recurrence was reduced with less axillary surgery when compared with ALND was uncertain (HR 0.90, 95% CI 0.75 to 1.09; 24,176 participant-years of follow up; eight studies). Locoregional recurrence was more likely with less surgery than with ALND (HR 1.53, 95% CI 1.31 to 1.78; 26,880 participant-years of follow-up; seven studies). Whether risk of distant metastasis was increased after less axillary surgery compared with ALND was uncertain (HR 1.07, 95% CI 0.95 to 1.20; 2665 participants; five studies). Lymphoedema was less likely after less axillary surgery than with ALND (OR 0.37, 95% CI 0.29 to 0.46; 3964 participants; nine studies).No studies reported on disease control in the axilla.

AUTHORS' CONCLUSIONS

This review confirms the benefit of SLNB and axillary sampling as alternatives to ALND for axillary staging, supporting the view that ALND of the clinically and radiologically uninvolved axilla is no longer acceptable practice in people with breast cancer.

Axillary sampling and the risk of erroneous staging of breast cancer. An analysis of 960 consecutive patients

Axillary nodal status was analysed in 960 consecutive cases of primary invasive breast cancer operated in two Danish hospitals. After stratification according to the number of nodes removed, the rate of node positivity in each subgroup was calculated. We found that the probability of finding at least one metastatic node increased continuously up to about 10 removed nodes. In lymph node negative patients, who did not receive any adjuvant treatment, there was a significant association between the recurrence-free survival and the number of nodes removed, provided that less than 8-10 nodes had been collected. The percentage of node positivity in each subgroup seemed to level off above 10 nodes at about 64%, suggesting that this represents the true rate of node positivity at the time of primary surgery. We conclude that about 10 axillary nodes should be removed in order to minimize the risk of erroneous classification of the axilla.

Probability of false negative nodal staging in conjunction with partial axillary dissection in breast cancer

There is a risk of overlooking lymph node metastases and thereby contributing to inaccurate nodal staging when performing partial axillary dissection in conjunction with total mastectomy in female breast cancer. The Danish Breast Cancer Cooperative Group (DBCG) analysed this risk in a prospective nation-wide adjuvant trial dealing with primary operable breast carcinoma. The series comprised 3114 patients, initially found to have lymph node negative axillae, followed for a median of 24 months (quartiles 12-40). It was found that the probability of early ipsilateral axillary relapse of cancer, estimated by means of the life table method, decreased with the number of nodes removed. After 2 years the recurrence rate was 12 per cent for patients with no lymph nodes removed, 7 per cent with one or two nodes removed and 2 per cent with three or more nodes removed. It is concluded that the risk of false negative nodal staging in conjunction with partial axillary dissection is modest, provided at least three lymph nodes are removed and found to be negative on histological examination.

Considerations of cost and effectiveness in the choice of mastectomy

Operable breast cancer may be managed equally well by a number of different regimens of mastectomy and/or radiotherapy. This paper examines the financial and morbidity costs, together with the node sampling efficacy, of three commonly employed techniques: simple mastectomy; total mastectomy with node biopsy or limited node excision; and modified radical mastectomy. Adjuvant radiotherapy (and/or chemotherapy) can only be applied rationally if node sampling is effective. Simple mastectomy cannot achieve this. Total mastectomy, providing that a node sample is obtained, is effective, and is probably the cheapest option. Total axillary clearance runs the risk of increased morbidity (and financial cost), while not necessarily guaranteeing more effective node sampling. Much of the cost and morbidity of mastectomy may be reduced by a limited but rational radiation policy.

A potpourri of RCT topics

(1. Randomization of the first patient. At least six examples are known to the author, and there are undoubtedly others. (2. Factorially structured treatments. The advantages of conducting two trials in the same patients when there is no suggestion of interaction, and documenting interaction if it exists must be weighed against the potential loss of power and the inconvenience of missing values. (3. RCT control groups as a source of unnatural history. Such a small percentage of apparently suitable patients are actually randomized in most clinical trials that be control group can never the considered representative of that disease seen by practicing physicians. (4. Bias in random and nonrandom treatment assignments. Differences in risk factors documented before randomization can be as much responsible for differences in outcome as the treatments under study. (5. Time lags between innovation, RCTs, and practice. These have varied from a very few years (coronary bypass operations) to 154 years (treatment of scurvy).

Treatment of early breast cancer

The early follow-up of patients treated by simple mastectomy alone or simple mastectomy combined with radical radiotherapy is presented. Both groups were well matched for age, menopausal status, duration of symptoms, size of tumour, and lymph-node involvement. There was no significant difference in survival of patients in the two groups at three years, but local recurrence was significantly more frequent (28%) in the mastectomy-alone patients. Early survival was not adversely affected by radiotherapy.

Observer variation in recording clinical data from women presenting with breast lesions. Report from the Yorkshire Breast Cancer Group

The degree of observer variation in recording 11 186 items of clinical data from 242 woman who presented complaining of a lump in the breast to a group of 10 surgeons was studied. Each women was interviewed and examined twice and the findings (of the two clinicians) compared. There was a wide range of variation among the observers. Variation in recording the presence or absence of axillary nodes was considerable (45%), as was that in sizing the primary lesion (55%). In 20% of cases the two assessments of primary lesion size differed by over 2 cm. In other respects the results were more encouraging; much variation could be eliminated by wording the proforma more clearly. Moreover, variation was not person-specific, so that these findings are probably reasonably representative. Any future trial of breast lesions should (a) design specific proformata, (b) define terminology, (c) make these definitions universally available, and (d) conduct observer variation studies before the start of the full trial.

Conservative local treatment of breast cancer

A survey of controlled randomized trials of orthodox therapy directed to the breast and axillary nodes has indicated that 1) if radical mastectomy is performed, postoperative radiotherapy gives no advantage over a watching policy and 2) if postoperative radical radiotherapy is given, there is no need for other than a simple mastectomy. A large multicenter trial is also indicating that simple mastectomy alone with reservation of radiotherapy for treating local recurrent disease is safe initial treatment. These results refer to survival; postoperative radiotherapy does reduce the incidence of local recurrence but this apparently can be equally well treated when it occurs. Local excision of the tumor, followed by radiotherapy, has been reported to give inferior results to a radical approach in Stage II tumors. Recognition that all these methods of local treatment fail to cure the majority of patients has emphasized the need to define the extent of the disease and to apply treatment according to that extent. We have studied a policy of selective local therapy based on this principal in which total mastectomy is combined with biopsy of the pectoral lymph nodes and further treatment by radiotherapy given only if these nodes are involved by tumor. This policy has been compared with a standard radical approach and is giving similar results. In our current Edinburgh trials, pectoral node biopsy is also used to select patients for inclusion in trials of systemic therapy.

Simple mastectomy and pectoral node biopsy

Evidence is presented to support the view that biopsy of the pectoral and axillary tail nodes obtained at simple (total) mastectomy gives a reliable estimate of axillary node status. The technique is described.

Management of early cancer of the breast. Report on an international multicentre trial supported by the Cancer Research Campaign

In the largest controlled clinical study so far undertaken on the management of early cancer of the breast in women the results of a radical regimen (simple mastectomy and radiotherapy) were compared with those of a conservative policy (simple mastectomy alone). The study included enough patients (2268) to ensure that small but significant differences between the two treatments would emerge. With a five-year follow-up there was no evidence that routine postoperative radiotherapy was harmful or that it conferred further benefit as regards survival or distant recurrence. Radiotherapy did, however, reduce the incidence of local recurrence. Neither form of treatment can counter occult disease far from the breast that is present at the time of initial treatment, which probably accounts for the high death rate from breast cancer, but the results of the study would support the view that conservative primary treatment and subsequent adjuvant chemotherapy may be the treatment of choice in future.

On the staging of breast carcinoma

The implications of the new staging system for breast carcinoma proposed in 1973 by the International Union Against Cancer (UICC) in conjunction with the American Joint Committee on Cancer Staging and End Results (AJC) has been examined both in terms of staging distribution and the presentation of survival results as compared with the currently used International staging classification in a large consecutive series of patients referred for treatment between 1960-62. The new UICC/AJC system, if accepted, will require some 23% of cases at present Stage II (International) to be allocated to Stage I depending on a clinical assessment as to whether the nodes are involved or not. It will result in the reporting of increased survival rates for Stage I and Stage II disease, and this change is sufficiently large to be of statistical significance in Stage I disease at five and ten years.

Lymph-node biopsy during simple mastectomy

The distribution of pectoral (external mammary) nodes identified during the operation and removed with the axillary tail of the breast was studied in 45 patients treated by simple (total) mastectomy. Up to 13 nodes may lie within the axillary tail, and these are continuous with the pectoral nodes. Lymph-nodes were identified in 90 percent of patients treated by simple (total) mastectomy without dissection of the axilla.

The delayed hypersensitivity reaction in breast cancer

Women with breast cancer confined to the breast (stage I) have a reduced dermal delayed hypersensitivity reaction to Varidase; the degree of anergy to this antigen increases as the disease progresses. The in vitro reaction to phytohaemagglutinin, however, remains normal throughout the course of the disease.