The aim of this study was to evaluate the feasibility of BCT performed by residents in training. Our data confirm that lumpectomy for carcinoma can be performed safely by residents in training, resulting in comparable numbers of negative margins for palpable carcinomas in resection specimens for operations performed by SRs, ASs, and JRs when supervised by an attending surgeon or assisted by another resident.
Nonpalpable carcinomas, however, show a substantial increase in the number of positive margins when operated on by JRs. Data show that this increase in nonradical resections is absolute and not dependent on the level of supervision given during the operation. This suggests that JRs do not have the necessary surgical skills to perform a lumpectomy for a nonpalpable carcinoma resulting in negative margins in resection specimens.
Reported rates of incomplete excisions
The rates of 13% for incomplete excisions for palpable tumors and 22% for nonpalpable tumors are comparable with rates found in literature. Moorthy et al. [
13] reported a re-excision rate of 21% for palpable tumors and 32% for nonpalpable tumors. Regarding re-excisions, Dixon et al. [
11] reported on patients with nonpalpable tumors who were operated on by unsupervised residents resulting in a higher rate of re-excisions (57% vs. 4%). However, no distinction was made in level of experience of the resident. Recently, Moorthy et al. [
13] showed no difference in re-excision rates between attending surgeons and residents who were in their final years of training (AS 27.8% and SRs 25.7%). Furthermore, Landheer et al. [
12] reported no difference in margin-free resection between surgeons and residents, but made no distinction between palpable and nonpalpable tumors or level of experience of the residents. Our findings support the idea that BCT for palpable tumors can be performed safely by residents in training. Extrapolation of our data to other clinics should be made with caution because our hospital is a high-volume center for breast surgery (approximately 200 cases/year). Treatment in hospitals that perform more than 150 operations per year have a reduced risk of death by 33% compared to low-volume hospitals [
10,
16].
The present study shows that obtaining tumor-free margins is dependent on whether the breast carcinoma is palpable or nonpalpable when performing a lumpectomy. We also demonstrated that the lumpectomies that were performed for nonpalpable tumors resulting in positive margins had a significantly smaller volume compared to radical resections. Secondary tumor characteristics were not shown to differ or have significant influence between operator groups.
In contrast to previous reports, we could not show a significant influence on completeness of excision for age of the patient, tumor size, tumor localization, histopathologic subtype, differentiation grade, presence of
in situ component, and adequacy of wire localization [
17‐
21]. Previous reports suggest a higher risk for incomplete excisions in younger patients [
17,
18] and when dealing with larger tumor sizes [
19‐
21]. Horiguchi et al. [
22], however, could not show that age, tumor size, lymph node status, and clinical stage had an effect on completeness of excision. Moorthy et al. [
13] and Tarrter et al. [
17] showed that patients who underwent a lumpectomy in the absence of a positive tissue diagnosis had a higher risk for re-excision. This could not be confirmed by our data.
Essentially, lumpectomy for nonpalpable tumors is different from lumpectomy for palpable tumors in that the former requires higher surgical skills such as the ability to make a three-dimensional mental image of the operating field. With palpable lesions the performing surgeon has a constant reference of macroscopic tumor margins by palpation of the tumor. Results of the present study show that surgical residents in training can safely perform BCT for palpable breast tumors. Senior residents can perform the operation without the supervision of an attending surgeon.
For all attending surgeons and all senior residents, the number of breast-conserving operations performed at the start of the time interval for inclusion in this study was more than 75 and 25 procedures, respectively. Junior residents had a mean number of performed breast-conserving operations of less than 10. Accordingly, the minimum experience for breast-conserving surgery for nonpalpable breast carcinoma should be 25 procedures. It should be kept in mind, however, that ongoing experience and thus adequate surgical exposure each year for the surgeons performing these operations should be available. We state that for training hospitals, “senior residents after proper training and exposure can do the job.”
Ideally, nonpalpable tumors should be reserved for a dedicated surgeon. Palpable tumors can be managed by a nonspecialized surgeon, but it should be kept in mind that adequate exposure is mandatory.
Successful complete excisions of nonpalpable breast tumors are dependent on the level of experience of the operating surgeon. Our data indicate that nonpalpable tumors should not be operated on by junior residents, even if supervised by an attending surgeon. This suggests that for nonpalpable breast cancer, radicality of resection is strongly influenced by the surgical experience of the resident performing the operation.