Conservative surgery in breast cancer. Significance of resection margins

Ten-year results of applying an original scoring system for addressing adjuvant therapy use after breast-conserving surgery for ductal carcinoma in situ of the breast

PURPOSE

Although large-scale randomised clinical trials have established that radiotherapy (RT) - alone or combined with hormonal therapy (HT) - is effective in reducing the risk of ipsilateral breast tumour recurrence (IBTR), overall survival does not seem to be improved by adjuvant therapies. We sought to ascertain whether specific criteria can be adopted to avoid RT with an acceptable rate of IBTR after breast-conserving surgery (BCS) achieving tumour-free margins.

PATIENTS AND METHODS

This non-randomised prospective study concerned the outcome of patients who underwent BCS for ductal carcinoma in situ (DCIS) and were prospectively assessed by means of an established scoring system based on width of free margins in association with age <40, presence of comedonecrosis, high grade, ER negativity and HER2 positivity, to orient the use of any adjuvant therapies.

RESULTS

From March 2000 to April 2006, a total of 224 patients were enrolled and followed up for this study. No adjuvant treatment was considered for 76 patients, while 53, 39 and 56 patients received HT alone, RT alone, and RT plus HT, respectively. After a median follow-up of 129.6 months, 25 patients developed an IBTR, corresponding to a yearly rate of 1.138% (95% CI: 0.769-1.684).

CONCLUSION

When the criteria considered in the present study were applied to address the use of adjuvant therapies, no RT was administered to 57.6% of patients, 33.9% received no adjuvant treatments at all, and the rate of IBTR was low. Our findings support the conviction that the risk/benefit of omitting RT may lean on the side of the latter in selected patients.

How does knowledge of three-dimensional excision margins following breast conservation surgery impact upon clinical target volume definition for partial-breast radiotherapy?

BACKGROUND AND PURPOSE

To compare partial-breast clinical target volumes generated using a standard 15 mm margin (CTV(standard)) with those generated using three-dimensional surgical excision margins (CTV(tailored 30)) in women who have undergone wide local excision (WLE) for breast cancer.

MATERIAL AND METHODS

Thirty-five women underwent WLE with placement of clips in the anterior, deep and coronal excision cavity walls. Distances from tumour to each of six margins were measured microscopically. Tumour bed was defined on kV-CT images using clips. CTV(standard) was generated by adding a uniform three-dimensional 15 mm margin, and CTV(tailored 30) was generated by adding 30 mm minus the excision margin in three-dimensions. Concordance between CTV(standard) and CTV(tailored 30) was quantified using conformity (CoI), geographical-miss (GMI) and normal-tissue (NTI) indices. An external-beam partial-breast irradiation (PBI) plan was generated to cover 95% of CTV(standard) with the 95% isodose. Percentage-volume coverage of CTV(tailored 30) by the 95% isodose was measured.

RESULTS

Median (range) coronal, superficial and deep excision margins were 15.0 (0.5-76.0)mm, 4.0 (0.0-60.0)mm and 4.0 (0.5-35.0)mm, respectively. Median CoI, GMI and NTI were 0.62, 0.16 and 0.20, respectively. Median coverage of CTV(tailored 30) by the PBI-plan was 97.7% (range 84.9-100.0%). CTV(tailored 30) was inadequately covered by the 95% isodose in 4/29 cases. In three cases, the excision margin in the direction of inadequate coverage was <or=2mm.

CONCLUSIONS

CTVs based on 3D excision margin data are discordant with those defined using a standard uniform 15 mm TB-CTV margin. In women with narrow excision margins, the standard TB-CTV margin could result in a geographical miss. Therefore, wider TB-CTV margins should be considered where re-excision does not occur.

Radioguided Intraoperative Margins Evaluation (RIME): Preliminary results of a new technique to aid breast cancer resection

AIMS

Women undergoing breast-conserving surgery for cancer can present residual disease. We have developed a technique called Radioguided Intraoperative Margins Evaluation (RIME) that uses a radiopharmaceutical to distinguish normal and cancer tissues. The aim of this study was to assess whether RIME is a feasible technique, and if it could help in breast cancer resection with free margins, minimizing residual disease.

METHODS

Twenty-three breast cancer patients programmed for mastectomy were selected. Before surgery, the patients were submitted to scintimammography with 99mTc-sestamibi to estimate the optimal time to begin radioguided surgery. Twenty patients were submitted to magnetic resonance imaging (MRI), to evaluate skin, deep fascia and to detect other tumor foci. At the beginning of the surgery, the same dose of 99mTc-sestamibi was intravenously injected into patients. Tumor resection was performed under guidance of a gamma-probe, characterizing the RIME technique. Finally, modified radical mastectomy was performed. Tumor and residual breast were histopathologically examined.

RESULTS

The RIME technique was successfully performed in all patients. The principal tumor was removed by this technique and provided 82.6% of histologically free margins (mean margins, 4.8 mm). Additionally, 47.8% of patients were without residual disease. The mean size of residual carcinoma was 3.67 mm and generally located near the tumor bed (<1.5 cm). There was no significant association between presence of residual disease and tumor size or margin status.

CONCLUSION

RIME is a feasible technique that could help tumor resection with free margins; however, it seems to be limited for small carcinoma foci.

Oncoplastic surgery of the breast: Rationale and experience of 30 cases

A definition of oncoplastic surgery of the breast is presented, and its objectives and advantages over the usual conservative procedures are discussed. The oncological safety of these procedures are demonstrated, especially in surgery of larger tumors. Technical possibilities are discussed and a classification of the procedures presented. Data from 30 cases operated in our institution are depicted. The need for better training of the breast surgeon is discussed and the advantages of the same surgeon to perform the whole procedure presented.

Radioguided Surgery Using Intravenous 99mTc Sestamibi Associated with Breast Magnetic Resonance Imaging for Guidance of Breast Cancer Resection

The purpose of this study was to evaluate the feasibility of surgery radioguided with intravenous (99m)Tc sestamibi associated with magnetic resonance imaging (MRI) of the breast to detect tumor extent and guide complete tumor resection. A descriptive experimental study was developed with 10 breast cancer patients (stage IIA-IIB) who underwent mastectomy. From 2 to 10 days before surgery, the patients underwent breast MRI with 0.1 mmol/kg of gadolinium and scintimammography with a 740 MBq of (99m)Tc sestamibi. A region of interest was drawn around the tumor image and an uptake curve as a function of time was plotted to calculate the optimal time to perform radioguided surgery. In the perioperative period, the same dose of (99m)Tc sestamibi was intravenously injected into the patients. Tumor resection was performed under the guidance of a gamma probe. MRI was used to evaluate the skin and deep fascia involvement and to detect occult tumor foci which were also excised. Subsequently a modified radical mastectomy was performed. Tumor and residual breast were histopathologically examined. In a series of 10 women, all demonstrated (99m)Tc sestamibi uptake in tumor cells. Eight patients showed no disease in the residual breast, one presented with one foci of invasive ductal carcinoma measuring 0.5 cm in diameter located 5 cm from the tumor bed, and one presented with one foci of ductal carcinoma in situ measuring 0.8 cm at the resection margin. The mean tumor size in the histopathologic assessment was 3.3 cm and in MRI was 5.0 cm. Radioguided surgery using (99m)Tc sestamibi associated with MRI is a feasible technique that can be employed in tumor resection.

Rates for mastectomy are lower in women attending a breast-screening programme

BACKGROUND

Mammographic screening for breast cancer facilitates earlier recognition of lesions, thus potentially allowing for breast-conserving surgery. Few studies have compared the final surgical outcomes of women presenting through breast screening programmes with those presenting via other sources. Are breast cancer patients presenting through BreastScreen more likely to undergo breast-conserving surgery than those presenting from other sources?

METHODS

Using the Royal Perth Hospital (RPH) Multidisciplinary Breast Service Database, the final surgical outcomes were reviewed for 723 women treated for breast cancer at RPH between January 2000 and August 2002. During this period, 397 patients were referred to the RPH Multidisciplinary Breast Clinic from BreastScreen WA, and 326 were referred from other sources.

RESULTS

Of all patients undergoing surgery for breast cancer, 58% in the screen group and 36% in the non-screen group had breast-conserving surgery (P < 0.0001). When surgical outcomes for women in the BreastScreen target age range of 50-69 years were analysed, 59.5% in the screen group and 42.3% in the non-screen group had breast-conserving surgery (P < 0.001). Patient choice was second only to disease extent as a factor determining the outcome of mastectomy. In both cohorts, more than 40% of patients who underwent re-excisional surgery for positive margins, after initial breast-conserving surgery, had residual invasive or in situ disease present.

CONCLUSIONS

At RPH, BreastScreen patients were more likely to undergo breast-conserving surgery than those who presented from other sources. A significant proportion of women with positive margins after initial breast-conserving surgery had residual in situ or invasive disease. Re-excision for positive margins was thus warranted.

Effect of cavity margin shavings to ensure completeness of excision on local recurrence rates following breast conserving surgery

AIMS

The presence of residual disease at the excision margin after breast conserving surgery is the most important risk factor for local recurrence. One method for assessing tumour margin involvement is to take shavings from the wall of the resulting cavity following wide excision of the lesion.

METHODS

We have reviewed our experience of shaving the margin of the cavity as our method to ensure completeness of excision.

RESULTS

Of 351 patients treated with breast conservation 61 patients had residual disease in the cavity margin biopsies. Younger age, axillary lymph node status, multi-focal tumours and high grade tumours were significantly correlated with margin involvement. In patients who had clear margins eight patients (2.8%) had developed a local recurrence at follow-up of 55 months (25-89 months).

CONCLUSIONS

In our hands the use of cavity margin shavings allows us to achieve an acceptable rate of local control.