DISCUSSION:
The excision volume required to safely perform BCS can be reduced by
neoadjuvant therapy (12). Regardless of the administration of
neoadjuvant therapy, poor cosmetic outcomes are obtained in cases where
large excisions are required to perform BCS (13). Furthermore, surgical
margin positivity and re-excision rates are quite high after BCS (14).
Oncoplastic surgery allows larger volume excision without impairing
cosmetic outcomes and reduces re-excision rates (15). Primary tumor size
decreases after neoadjuvant therapy. In such cases, the success of the
treatment in terms of local control depends on the accurate tumor
localization. It is aimed to excise the accurate area at sufficient
volume after NAC by marking the tumor in the pre-NAC period, determining
localization by means of seeds containing radioactive material, and
applying intraoperative USG. However, pre-NAC marking cannot adequately
guide the clinician for tumors showing non-concentric shrinkage
patterns. Intraoperative localization techniques may remain inadequate
in this regard (16,17). In tumors that shrink into fragments, the
residual radiological disease should be evaluated and, if necessary,
marked after NAC. At this point, the question of whether unplanned
surgery can provide safe oncological results should arise. The answer to
this question has been investigated in patients who primarily underwent
BCS. In the National Surgical Adjuvant Breast and Bowel Project (NSABP)
Protocol B-18 trial, the local recurrence rate was reported to be 15.9%
in unplanned surgery and 9.3% in planned surgery. The difference was
statistically significant (2). The European Organization for Research
and Treatment of Cancer (EORTC) 10920 trial reported higher local
recurrence rates with unplanned surgery (3). In a study by Shin et al.
(10) involving patients with stage III breast cancer, the results of
planned BCS, unplanned BCS, and mastectomy were compared in patients
with a tumor size of less than 4 cm after NAC. The authors reported that
five-year LRFS was 90.9% in patients undergoing unplanned surgery,
while this rate was 96.3% in patients undergoing mastectomy (10). In
the series published by Fitzal et al. (9), BCS was performed in 110 of
221 patients scheduled for mastectomy before NAC. While unplanned
surgery was observed to have no disadvantage in terms of local control
in patients with a good response to NAC, local recurrence rates were
found to be higher in the unplanned surgery arm in patients with an
insufficient response. The technique used in all these studies was BCS,
but the neoadjuvant therapy criteria were not standard. It should be
kept in mind that the number of patients receiving neoadjuvant therapy
and the rate of responses to treatment have increased at the present
time. Furthermore, advanced imaging techniques may increase the
possibility of localization after NAC.
More than 20% of breast volume and a significant amount of breast skin
is excised in Level II techniques and simultaneous reconstruction is
performed with more complicated and sophisticated glandular flap
methods. On the other hand, less than 20% of the total breast volume is
excised and the volume excision is limited in Level I techniques.
Youssef et al. (18) presented post-NAC OPS results in a series of 70
patients. In this series where tumor marking was not performed before
NAC, the rate of IBTR was reported as 4.2% and Level I OPS techniques
were applied to %57 of the patients. The mean surgical margin distance
was found to be wider in patients for whom Level II techniques were
applied (25 mm vs. 10 mm). In the present series, Level II OPS
techniques were applied to all of our patients. Although not
statistically significant, the mean surgical margin distance was found
to be wider in the unplanned surgery group (18 mm vs. 14 mm). Surgeons
likely tend to excise more tissue to provide a firm surgical margin in
unmarked patients. In a study by Chauhan et al. (19), patients who
underwent OPS and BCS after NAC were compared. In the whole series,
reduction in the form of fragmentation was detected at a rate of 44%
and the tumor bed was marked with a clip in all patients before NAC.
Skin tattooing was performed, if necessary, to promote localization
after NAC. While the mean specimen volume and mean surgical margin
distance were larger in patients undergoing OPS, the ratio of involved
margin and IBTR was lower. In the literature, IBTR rates in patients
undergoing planned OPS after NAC were observed to range from 6% to 10%
(20,21). A matching case-control study comparing patients who underwent
BCS and OPS after NAC was reported from Brazil. Planned surgery was
applied to all patients. In this series, the majority of which consisted
of patients with T3 tumors, the volume of the excised specimen and mean
surgical margin distance were larger in the OPS group. During an average
follow-up of 67 months, the rate of IBTR was found to be 10.2%. In this
series, Level I OPS techniques were applied to nearly half of the
patients in the OPS group. Longer follow-up time and non-standardized
surgical techniques may explain the high local recurrence rates in this
series (22). Similar results were reported by Mazouni et al. (23) from
France. Pre-NAC primary tumor marking was not standard in this series.
Post-NAC tumor size and specimen volume were found to be larger in
patients undergoing OPS. The re-excision rate was reported to be 2% in
patients undergoing OPS whereas it was 9% in patients undergoing BCS.
The requirement for mastectomy was 24% vs 18%, respectively, in
patients who underwent BCS and OPS (23). In our series, there were no
patients who underwent conventional BCS. Although re-excision rates in
patients who underwent OPS were found to be higher in our series
compared to the said study, the requirement for mastectomy was found to
be lower in patients undergoing planned and unplanned OPS. Five-year 5%
local recurrence rates, on the other hand, were found to be similar to
our series.
In the present series, mastectomy was performed after systemic treatment
in the presence of extensive skin involvement, skin edema, chest wall
involvement, and diffuse microcalcification. Performing mastectomy in
patients with any of these conditions is currently considered as
standard treatment. However, we were able to successfully perform OPS
after systemic therapy in our patients in the presence of minimal edema
and skin shrinkage around the tumor. This feature makes the present
study different from others.
Tumor shrinkage after NAC in locally advanced breast cancer may occur in
three ways. First, a complete clinical response can be seen in the
tumor. In this case, pre-NAC tumor marking makes the planning of
surgical treatment easier; however, the previous tumor bed can be still
displayed in post-NAC radiological examinations. Surgery can be planned
by taking this area as the center. Secondly, tumor sizes can be reduced
and a concentric response can be achieved, and no tumor nodules may be
seen in the periphery of the tumor. In this case, surgery can be planned
by taking residual tumor as a basis in the post-NAC period. The third
shrinkage pattern is called the mosaic pattern, where the tumor shrinks
by breaking into small pieces. In this case, pre-NAC marking of the
tumor is not sufficient to perform the surgery safely. The margins of
the nodules located in the periphery of the tumor should be known or
marked in the post-NAC period. Secondary surgical intervention is
mandatory for patients with involved resection margins, resulting in
poor cosmetic outcomes or loss of the breast. It further means increased
costs and psychological stress for the patient. The marking of the tumor
in both pre- and post-NAC periods is likely to be more meaningful.
Figures 2 and 3 present images related to OPS performed with post-NAC
wire localization on the patient with a tumor that shrank concentrically
with NAC.
This study has shown that BCS can be applied using level II OPS
techniques with the post-NAC radiological examination and marking even
if primary tumor marking is not done in the pre-NAC period. The rates of
re-excision and mastectomy requirement similar to the patients
undergoing planned OPS and mastectomy have been obtained in those
undergoing post-NAC unplanned OPS. Furthermore, long-term local control
rates are similar. The absence of pre-NAC primary tumor marking is not a
condition that necessarily requires a mastectomy. Moreover, localized
skin involvement and localized edema should not be considered a
contraindication for OPS.
A cknowledgements:
None
Statement of Ethics : This study was conducted with the
permission of the local ethics committee. Ethics committee approval
number: AOH/125/12
InformedConsent: Written informed consent was obtained from
patients who participated in this study.