Viviana Galimberti

Radiotherapy after Breast-Preserving Surgery in Women with Localized Cancer of the Breast

BACKGROUND AND METHODS Conservative surgery and radiotherapy have become well-established treatments for breast cancer, and many trials in progress are attempting to define the most acceptable type of procedure. Between 1987 and 1989 we randomly assigned 567 women with small breast cancers (< 2.5 cm in diameter) to quadrantectomy followed by radiotherapy or to quadrantectomy without radiotherapy. All patients underwent total axillary dissection. The median follow-up period was 39 months (range, 28 to 54). RESULTS The incidence of local recurrence was 8.8 percent among the patients treated with quadrantectomy without radiotherapy, as compared with 0.3 percent among those treated with postsurgical radiotherapy (P = 0.001). However, there was a substantial effect of age: patients more than 55 years old who did not receive radiotherapy had a low rate of local recurrence (3.8 percent). The four-year overall survival was similar in the two treatment groups. CONCLUSIONS Administering radiotherapy after quadrantectomy reduces the risk of local recurrence in women with small cancers of the breast, but radiotherapy may not be necessary in elderly women.

Axillary dissection versus no axillary dissection in patients with sentinel-node micrometastases (IBCSG 23–01): a phase 3 randomised controlled trial

BACKGROUND For patients with breast cancer and metastases in the sentinel nodes, axillary dissection has been standard treatment. However, for patients with limited sentinel-node involvement, axillary dissection might be overtreatment. We designed IBCSG trial 23-01 to determine whether no axillary dissection was non-inferior to axillary dissection in patients with one or more micrometastatic (≤2 mm) sentinel nodes and tumour of maximum 5 cm. METHODS In this multicentre, randomised, non-inferiority, phase 3 trial, patients were eligible if they had clinically non-palpable axillary lymph node(s) and a primary tumour of 5 cm or less and who, after sentinel-node biopsy, had one or more micrometastatic (≤2 mm) sentinel lymph nodes with no extracapsular extension. Patients were randomly assigned (in a 1:1 ratio) to either undergo axillary dissection or not to undergo axillary dissection. Randomisation was stratified by centre and menopausal status. Treatment assignment was not masked. The primary endpoint was disease-free survival. Non-inferiority was defined as a hazard ratio (HR) of less than 1·25 for no axillary dissection versus axillary dissection. The analysis was by intention to treat. Per protocol, disease and survival information continues to be collected yearly. This trial is registered with ClinicalTrials.gov, NCT00072293. FINDINGS Between April 1, 2001, and Feb 28, 2010, 465 patients were randomly assigned to axillary dissection and 469 to no axillary dissection. After the exclusion of three patients, 464 patients were in the axillary dissection group and 467 patients were in the no axillary dissection group. After a median follow-up of 5·0 (IQR 3·6-7·3) years, we recorded 69 disease-free survival events in the axillary dissection group and 55 events in the no axillary dissection group. Breast-cancer-related events were recorded in 48 patients in the axillary dissection group and 47 in the no axillary dissection group (ten local recurrences in the axillary dissection group and eight in the no axillary dissection group; three and nine contralateral breast cancers; one and five [corrected] regional recurrences; and 34 and 25 distant relapses). Other non-breast cancer events were recorded in 21 patients in the axillary dissection group and eight in the no axillary dissection group (20 and six second non-breast malignancies; and one and two deaths not due to a cancer event). 5-year disease-free survival was 87·8% (95% CI 84·4-91·2) in the group without axillary dissection and 84·4% (80·7-88·1) in the group with axillary dissection (log-rank p=0·16; HR for no axillary dissection vs axillary dissection was 0·78, 95% CI 0·55-1·11, non-inferiority p=0·0042). Patients with reported long-term surgical events (grade 3-4) included one sensory neuropathy (grade 3), three lymphoedema (two grade 3 and one grade 4), and three motor neuropathy (grade 3), all in the group that underwent axillary dissection, and one grade 3 motor neuropathy in the group without axillary dissection. One serious adverse event was reported, a postoperative infection in the axilla in the group with axillary dissection. INTERPRETATION Axillary dissection could be avoided in patients with early breast cancer and limited sentinel-node involvement, thus eliminating complications of axillary surgery with no adverse effect on survival. FUNDING None.

Loss of negative regulation by Numb over Notch is relevant to human breast carcinogenesis

The biological antagonism between Notch and Numb controls the proliferative/differentiative balance in development and homeostasis. Although altered Notch signaling has been linked to human diseases, including cancer, evidence for a substantial involvement of Notch in human tumors has remained elusive. Here, we show that Numb-mediated control on Notch signaling is lost in ∼50% of human mammary carcinomas, due to specific Numb ubiquitination and proteasomal degradation. Mechanistically, Numb operates as an oncosuppressor, as its ectopic expression in Numb-negative, but not in Numb-positive, tumor cells inhibits proliferation. Increased Notch signaling is observed in Numb-negative tumors, but reverts to basal levels after enforced expression of Numb. Conversely, Numb silencing increases Notch signaling in normal breast cells and in Numb-positive breast tumors. Finally, growth suppression of Numb-negative, but not Numb-positive, breast tumors can be achieved by pharmacological inhibition of Notch. Thus, the Numb/Notch biological antagonism is relevant to the homeostasis of the normal mammary parenchyma and its subversion contributes to human mammary carcinogenesis.

Sentinel-lymph-node biopsy as a staging procedure in breast cancer: update of a randomised controlled study

BACKGROUND In women with breast cancer, sentinel-lymph-node biopsy (SLNB) provides information that allows surgeons to avoid axillary-lymph-node dissection (ALND) if the SLN does not have metastasis, and has a favourable effect on quality of life. Results of our previous trial showed that SLNB accurately screens the ALN for metastasis in breast cancers of diameter 2 mm or less. We aimed to update this trial with results from longer follow-up. METHODS Women with breast tumours of diameter 2 cm or less were randomly assigned after breast-conserving surgery either to SLNB and total ALND (ALND group), or to SLNB followed by ALND only if the SLN was involved (SLN group). Analysis was restricted to patients whose tumour characteristics met eligibility criteria after treatment. The main endpoints were the number of axillary metastases in women in the SLN group with negative SLNs, staging power of SLNB, and disease-free and overall survival. FINDINGS Of the 257 patients in the ALND group, 83 (32%) had a positive SLN and 174 (68%) had a negative SLN; eight of those with negative SLNs were found to have false-negative SLNs. Of the 259 patients in the SLN group, 92 (36%) had a positive SLN, and 167 (65%) had a negative SLN. One case of overt clinical axillary metastasis was seen in the follow-up of the 167 women in the SLN group who did not receive ALND (ie, one false-negative). After a median follow-up of 79 months (range 15-97), 34 events associated with breast cancer occurred: 18 in the ALND group, and 16 in the SLN group (log-rank p=0.6). The overall 5-year survival of all patients was 96.4% (95% CI 94.1-98.7) in the ALND group and 98.4% (96.9-100) in the SLN group (log-rank p=0.1). INTERPRETATION SLNB can allow total ALND to be avoided in patients with negative SLNs, while reducing postoperative morbidity and the costs of hospital stay. The finding that only one overt axillary metastasis occurred during follow-up of patients who did not receive ALND (whereas eight cases were expected) could be explained by various hypotheses, including those from cancer-stem-cell research.

Sentinel lymph node biopsy in breast cancer: ten-year results of a randomized controlled study.

Objective:Sentinel node biopsy (SNB) is widely used to stage the axilla in breast cancer. We present 10-year follow-up of our single-institute trial designed to compare outcomes in patients who received no axillary dissection if the sentinel node was negative, with patients who received complete axillary dissection. Methods:From March 1998 to December 1999, 516 patients with primary breast cancer up to 2 cm in pathologic diameter were randomized either to SNB plus complete axillary dissection (AD arm) or to SNB with axillary dissection only if the sentinel node contained metastases (SN arm). Results:The 2 arms were well-balanced for number of sentinel nodes found, proportion of positive sentinel nodes, and all other tumor and patient characteristics. About 8 patients in the AD arm had false-negative SNs on histologic analysis: a similar number (8, 95% CI: 3–15) of patients with axillary involvement was expected in SN arm patients who did not receive axillary dissection; but only 2 cases of overt axillary metastasis occurred. There were 23 breast cancer-related events in the SN arm and 26 in the AD arm (log-rank, P = 0.52), while overall survival was greater in the SN arm (log-rank, P = 0.15). Conclusions:Preservation of healthy lymph nodes may have beneficial consequences. Axillary dissection should not be performed in breast cancer patients without first examining the sentinel node.

Quadrantectomy versus lumpectomy for small size breast cancer

Between 1985 and 1987 quadrantectomy plus external radiotherapy and lumpectomy plus external and interstitial radiotherapy were compared in a randomized trial of patients with small carcinomas of the breast. Quadrantectomy involves excision of 2-3 cm of normal tissue around the tumour plus the removal of a sufficiently large portion of overlying skin and underlying fascia whilst lumpectomy removes only the tumour mass with a narrow margin of normal tissue. Patients in both groups also received total axillary dissection. 705 cases were evaluable, 360 quadrantectomies and 345 lumpectomies. No differences in distant metastases and survival were observed in the two groups. However, lumpectomy patients had a much higher frequency of local recurrences (7.0 vs. 2.2%). Since a local recurrence needs a second operation and creates severe psychological distress to the patient, conservative surgical procedures should include generous excision of normal tissue around the primary carcinoma plus intensive postoperative radiotherapy.

Chemotherapy Is More Effective in Patients with Breast Cancer Not Expressing Steroid Hormone Receptors A Study of Preoperative Treatment

Purpose: The purpose of this research was to identify factors predicting response to preoperative chemotherapy. Experimental Design: In a large volume laboratory using standard immunohistochemical methods, we reviewed the pretreatment biopsies and histologic specimens at final surgery of 399 patients with large or locally advanced breast cancer (cT2-T4, N0–2, M0) who were treated with preoperative chemotherapy. The incidence of pathological complete remission and the incidence of node-negative status at final surgery were assessed with respect to initial pathological and clinical findings. Menopausal status, estrogen receptor status, progesterone receptor status [absent (0% of the cells positive) versus expressed], clinical tumor size, histologic grade, Ki-67, Her-2/neu expression, and type and route of chemotherapy were considered. Results: High rates of pathological complete remission were associated with absence of estrogen receptor and progesterone receptor expression (P < 0.0001), and grade 3 (P = 0.001). Significant predictors of node-negative status at surgery were absence of estrogen receptor and progesterone receptor expression (P < 0.0001), clinical tumor size <5 cm (P < 0.001), and use of infusional regimens (P = 0.003). The chance of obtaining pathological complete remission or node-negative status for patients with endocrine nonresponsive tumors compared with those having some estrogen receptor or progesterone receptor expression was 4.22 (95% confidence interval, 2.20–8.09, 33.3% versus 7.5%) and 3.47 (95% confidence interval, 2.09–5.76, 42.9% versus 21.7%), respectively. Despite the significantly higher incidence of pathological complete remission and node-negative status achieved by preoperative chemotherapy for patients with estrogen receptor and progesterone receptor absent disease, the disease-free survival was significantly worse for this cohort compared with the low/positive expression cohort (4-year disease-free survival %: 41% versus 74%; hazard ratio 3.22; 95% confidence interval, 2.28–4.54; P < 0.0001). Conclusions: Response to preoperative chemotherapy is significantly higher for patients with endocrine nonresponsive tumors. New chemotherapy regimens or combinations should be explored in this cohort of patients with poor outcome. For patients with endocrine responsive disease, the role of preoperative endocrine therapies should be studied.

NUMB controls p53 tumour suppressor activity

NUMB is a cell fate determinant, which, by asymmetrically partitioning at mitosis, controls cell fate choices by antagonising the activity of the plasma membrane receptor of the NOTCH family. NUMB is also an endocytic protein, and the NOTCH–NUMB counteraction has been linked to this function. There might be, however, additional functions of NUMB, as witnessed by its proposed role as a tumour suppressor in breast cancer. Here we describe a previously unknown function for human NUMB as a regulator of tumour protein p53 (also known as TP53). NUMB enters in a tricomplex with p53 and the E3 ubiquitin ligase HDM2 (also known as MDM2), thereby preventing ubiquitination and degradation of p53. This results in increased p53 protein levels and activity, and in regulation of p53-dependent phenotypes. In breast cancers there is frequent loss of NUMB expression. We show that, in primary breast tumour cells, this event causes decreased p53 levels and increased chemoresistance. In breast cancers, loss of NUMB expression causes increased activity of the receptor NOTCH. Thus, in these cancers, a single event—loss of NUMB expression—determines activation of an oncogene (NOTCH) and attenuation of the p53 tumour suppressor pathway. Biologically, this results in an aggressive tumour phenotype, as witnessed by findings that NUMB-defective breast tumours display poor prognosis. Our results uncover a previously unknown tumour suppressor circuitry.

Predicting the Risk for Additional Axillary Metastases in Patients With Breast Carcinoma and Positive Sentinel Lymph Node Biopsy

Objective:To assess whether the risk for nonsentinel node metastases may be predicted, thus sparing a subgroup of patients with breast carcinoma and a positive sentinel lymph node (SLN) biopsy completion axillary lymph node dissection (ALND). Summary Background Data:The SLN is the only involved axillary lymph node in the majority of the patients undergoing ALND for a positive SLN biopsy. A model to predict the status of nonsentinel axillary lymph nodes could help tailor surgical therapy to those patients most likely to benefit from completion ALND. Methods:All the axillary sentinel and nonsentinel lymph nodes of 1228 patients were reviewed histologically and reclassified according to the current TNM classification of malignant tumors as bearing isolated tumor cells only, micrometastases, or (macro)metastases. The prevalence of metastases in nonsentinel lymph nodes was correlated to the type of SLN involvement and the size of the metastasis, the number of affected SLNs, and the prospectively collected clinicopathologic variables of the primary tumors. Results:In multivariate analysis, further axillary involvement was significantly associated with the type and size of SLN metastases, the number of affected SLNs, and the occurrence of peritumoral vascular invasion in the primary tumor. A predictive model based on the characteristics most strongly associated with nonsentinel node metastases was able to identify subgroups of patients at significantly different risk for further axillary involvement. Conclusions:Patients with the most favorable combination of predictive factors still have no less than 13% risk for nonsentinel lymph node metastases and should be offered completion ALND outside of clinical trials of SLN biopsy without back-up axillary clearing.

Distribution of axillary node metastases by level of invasion. An analysis of 539 cases

Five hundred and thirty‐nine patients with carcinoma of the breast treated with total axillary dissection and with positive axillary nodes were evaluated. The total number of lymph nodes removed was 11,082, with an average of 20.5 nodes per patient. The average number of lymph nodes at the first level was 13.8, at the second level 4.5, at the third level 2.2. The average number of nodes was 20.7 in cases treated with Halsted mastectomy, 20.9 with total mastectomy and axillary dissection, 20.3 with quadrantectomy and axillary dissection. Of 3259 metastatic nodes, 64 were site of micrometastases; 797 were partially involved, 441 were totally involved and 1957 were site of metastases with extracapsular invasion. In 314 (58.2%) the first level only was involved, in 117 cases (21.7%) metastases were present at the first and second level, whereas in 88 cases (16.3%) all the three levels were sites of metastases. Only 20 cases showed skipping distribution. In 1.5% of the cases the first level was skipped by metastases, in 0.4% the first and second levels were both skipped. The predicting value of the first level is considerable: when the nodes of the first level are clear the chances that metastatic nodes are present at the second and third levels are negligible. When the nodes at the first level are positive, the chances that metastases are also present at the higher levels are of the order of 40.0%. Cancer 59:682‐687, 1987.