Six-year follow-up of patients with microinvasive, T1a, and T1b breast carcinoma

Incidence of Pathologic Nodal Disease in Clinically Node-Negative, Microinvasive or T1a Breast Cancers

BACKGROUND

Axillary staging in early-stage breast cancer can impact adjuvant treatment options but also has associated morbidity. The incidence of pathologic nodal positivity (pN+) in patients with microinvasive or T1a disease is poorly characterized and the value of sentinel node biopsy remains controversial.

METHODS

Women with cN0 and pathologic microinvasive or T1a cancer who underwent upfront surgery were identified from the National Cancer Database. Pathologic nodal stage at the time of surgery was the primary outcome. Multivariable logistic modeling was used to assess predictors of pN+.

RESULTS

Overall, 141,840 women were included; 139,206 had pathologic node-negative (pN0) disease and 2634 had pN+ disease. Rates of pN+ disease differed by receptor status, with the highest rates in hormone receptor-negative/human epidermal growth factor receptor 2-positive (HR-/HER2+) disease compared with triple-negative breast cancer (TNBC), HR-positive/HER2-negative (HR+/HER2-), and triple positive breast cancer. Rates of pN+ were also higher with lobular histology compared with ductal histology. Multivariable analysis demonstrated that compared with White women, Black women had higher odds of pN+ disease, and compared with women <50 years of age, women >70 years of age had higher odds of pN+ disease. Compared with women with HR+/HER2- disease, women with TNBC, triple-positive breast cancer, and HR-/HER2+ all had lower odds, and women with invasive lobular disease had higher odds compared with women with invasive ductal disease. Women with significant comorbidities also had higher odds of node positivity.

CONCLUSION

Over 90% of patients with clinically node-negative, microinvasive and T1a breast cancer remain pathologically node-negative following axillary staging. However, higher rates of nodal disease were found among Black patients, older patients, and patients with lobular cancer and significant comorbidities.

Molecular Subtype May Be More Associated With Prognosis and Chemotherapy Benefit Than Tumor Size in T1N0 Breast Cancer Patients: An Analysis of 2,168 Patients for Possible De-Escalation Treatment

Purpose

Breast cancer (BC) patients with T1N0 tumors have relatively favorable clinical outcomes. However, it remains unclear whether molecular subtypes can aide in prognostic prediction for such small, nodal-negative BC cases and guide decision-making about escalating or de-escalating treatments.

Patients and Methods

T1N0 BC patients diagnosed between 2009 and 2017 were included and classified into three subgroups according to receptor status: 1) hormonal receptor (HR)+/human epidermal growth factor receptor-2 (HER2)−; 2) HER2+; and 3) triple negative (TN) (HR−/HER2−). Patients’ characteristics and relapse events were reviewed. Kaplan–Meier analysis and Cox regression were used to assess the iDFS and BCSS. The effects of risk factors and adjuvant treatment benefits were evaluated by calculating hazard ratios (HRs) for invasive disease-free survival (iDFS) and breast cancer-specific survival (BCSS) with Cox proportional hazards models.

Results

In total, 2,168 patients (1,435 HR+/HER2−, 427 HER2+, 306 TN) were enrolled. The 5-year iDFS rates were 93.6, 92.7, and 90.6% for HR+/HER2−, HER2+, and TN patients, respectively (P = 0.039). Multivariate analysis demonstrated that molecular subtype (P = 0.043), but not tumor size (P = 0.805), was independently associated with iDFS in T1N0 BC. TN patients [HRs = 1.77, 95% confidence interval (CI) = 1.11–2.84, P = 0.018] had a higher recurrence risk than HR+/HER2− patients. Adjuvant chemotherapy benefit was not demonstrated in all T1N0 patients but interacted with molecular subtype status. TN (adjusted HRs = 2.31, 95% CI = 0.68–7.54) and HER2+ (adjusted HRs = 2.26, 95% CI = 0.95–5.63) patients receiving chemotherapy had superior iDFS rates. Regarding BCSS, molecular subtype tended to be related to outcome (P = 0.053) and associated with chemotherapy benefit (P = 0.005).

Conclusion

Molecular subtype was more associated with disease outcome and chemotherapy benefit than tumor size in T1N0 BC patients, indicating that it may guide possible clinical de-escalating therapy in T1N0 BC.

Is adjuvant chemotherapy necessary for patients with microinvasive breast cancer after surgery?

Objective: Survival and treatment of patients with microinvasive breast cancer (MIBC) remain controversial. In this paper, we evaluated whether adjuvant chemotherapy is necessary for patients with MIBC to identify risk factors influencing its prognosis and decide the indication for adjuvant chemotherapy. Methods: In this retrospective study, 108 patients with MIBC were recruited according to seventh edition of the staging manual of the American Joint Committee on Cancer (AJCC). The subjects were divided into chemotherapy and non-chemotherapy groups. We compared the 5-year disease-free survival (DFS) and overall survival (OS) rates between groups. Furthermore, we analyzed the factors related to prognosis for patients with MIBC using univariate and multivariate analyses. We also evaluated the impact of adjuvant chemotherapy on the prognostic factors by subgroup analysis after median follow-up time of 33 months (13-104 months). Results: The 5-year DFS and OS rates for the chemotherapy group were 93.7% and 97.5%, whereas those for the non-chemotherapy group were 89.7% and 100%. Results indicate that 5-year DFS was superior, but OS was inferior, in the former group compared with the latter group. However, no statistical significance was observed in the 5-year DFS (P=0.223) or OS (P=0.530) rate of the two groups. Most relevant poor-prognostic factors were Ki-67 overexpression and negative hormonal receptors. Cumulative survival was 98.2% vs. 86.5% between low Ki-67 (≤20%) and high Ki-67 (>20%). The hazard ratio of patients with high Ki-67 was 16.585 [95% confidence interval (CI), 1.969-139.724; P=0.010]. Meanwhile, ER(-)/PR(-) patients with MIBC had cumulative survival of 79.3% compared with 97.5% for ER(+) or PR(+) patients with MIBC. The hazard ratio for ER(-)/PR(-) patients with MIBC was 19.149 (95% CI, 3.702-99.057; P<0.001). Subgroup analysis showed that chemotherapy could improve the outcomes of ER(-)/PR(-) patients (P=0.014), but not those who overexpress Ki-67 (P=0.105). Conclusions: Patients with MIBC who overexpress Ki-67 and with negative hormonal receptors have relatively substantial risk of relapse within the first five years after surgery. However, adjuvant chemotherapy can only improve the outcomes of ER(-)/PR(-) patients, but not those who overexpress Ki-67. Further studies with prolonged follow-up of large cohorts are recommended to assess the prognostic significance and treatment of this lesion.

Predictive role of tumor size in breast cancer with axillary lymph node involvement - can size of primary tumor be used to omit an unnecessary axillary lymph node dissection?

BACKGROUND

Breast cancer is the most common cancer among women worldwide. The aim of this study was to investigate the relationship between tumor size and axillary lymph node involvement (ALNI) in patients with invasive lesions, to find the best candidates for a full axillary dissection. Additionally, we evaluated the association between tumor size and invasive behavior. The study was based on data from 789 patients with histopathologically proven invasive breast cancer diagnosed in Shohada University hospital in Tehran, Iran (1993-2009). Cinical and histopathological characteristics of tumors were collected. Patients were divided into 6 groups according to primary tumor size: group I (0.1-≤1cm), II (1.1-≤2cm), III (2.1-≤3cm), IV (3.1-≤4cm), V (4.1-≤5cm) and VI (>5cm). The mean(±SD) size of primary tumor at the time of diagnosis was 3.59±2.69 cm that gradually declined during the course of study. There was a significant correlation between tumor size and ALNI (p<0.001). A significant positive correlation between primary tumor size and involvement of surrounding tissue was also found (p<0.001). The mean number of LNI in group VI was significantly higher than other groups (p<0.05).We observed more involvement of lymph nodes, blood vessels, skin and areola-nipple tissue with increase in tumor size.We found 15.3% overall incidence of ALNI in tumors ≤2 cm, indicating the need for more investigation to omit full axillary lymph node dissection with an acceptable risk for tumors below this diameter. While in patients with tumors ≥2 cm, 84.3% of them had nodal metastases, so the best management for this group would be a full ALND. Tumor size is a significant predictor of ALNM and involvement of surrounding tissue, so that an exact estimation of the size of primary tumor is necessary prior to surgery to make the best decision for management of patients with invasive breast cancer.

Characteristics and clinical outcome of T1 breast cancer: a multicenter retrospective cohort study

BACKGROUND

A subgroup of T1N0M0 breast cancer (BC) carries a high potential of relapse, and thus may require adjuvant systemic therapy (AST).

PATIENTS AND METHODS

Retrospective analysis of all patients with T1 BC, who underwent surgery from January 1999 to December 2009 at 13 French sites. AST was not standardized.

RESULTS

Among 8100 women operated, 5423 had T1 tumors (708 T1a, 2208 T1b and 2508 T1c 11-15 mm). T1a differed significantly from T1b tumors with respect to several parameters (lower age, more frequent negative hormonal status and positive HER2 status, less frequent lymphovascular invasion), exhibiting a mix of favorable and poor prognosis factors. Overall survival was not different between T1a, b or c tumors but recurrence-free survival was significantly higher in T1b than in T1a tumors (P = 0.001). In multivariate analysis, tumor grade, hormone therapy and lymphovascular invasion were independent prognostic factors.

CONCLUSION

Relatively poor outcome of patients with T1a tumors might be explained by a high frequency of risk factors in this subgroup (frequent negative hormone receptors and HER2 overexpression) and by a less frequent administration of AST (endocrine treatment and chemotherapy). Tumor size might not be the main determinant of prognosis in T1 BC.

Implications of HER2 amplification in small, node-negative breast cancers: do Asians differ?

BACKGROUND

We investigated the implications of HER2 amplification in Asian women with small, node-negative breast cancer in low- and middle-income countries (LMCs).

METHODS

We reviewed the charts patients treated between 1989 and 2009 with breast conservation therapy for node-negative breast cancers measuring ≤ 2 cm. Disease-free survival (DFS), ipsilateral breast tumor recurrence (IBTR), distant disease-free survival (DDFS), and overall survival (OS) rates were estimated using the Kaplan-Meier method and were compared by the log-rank test. Potential covariates-age, tumor grade, hormone receptor status--were analyzed by multivariate analysis.

RESULTS

A total of 519 patients were studied including 204 (39%) and 315 (61%) patients diagnosed with pT1ab and pT1c tumors, respectively. Median follow-up was 57 months. HER2 amplification was found in 17.1% of all patients and in 16.7% patients with pT1ab tumors. Among patients with T1ab tumors, 73.0 and 9.3% underwent adjuvant hormonal and chemotherapy, respectively; 3 of 34 T1ab patients with HER2-amplified tumors received trastuzumab. HER2 amplification was associated with poorer 5-year DFS (83.7% vs. 95.5%, P < 0.0001), DDFS (87.5% vs. 97.9%, P < 0.0001), and IBTR (8.6% vs. 2.1%, P < 0.0001) rates in patients with pT1 tumors. Multivariate analysis showed that HER2 amplification remained a significant negative prognostic factor for DFS [hazard ratio (HR) 4.1, 95% confidence interval (CI) 2.1-7.8, P < 0.0001], DDFS (HR 6.3, 95% CI 2.4-17.0, P < 0.0001), and IBTR (HR 4.5, 95% CI 2.0-10.0, P < 0.0001) rates. In the pT1ab subgroup, univariate analysis showed that HER2 amplification prognosticated for DFS (85.1% vs. 95.7%, P = 0.022) and IBTR (14.9% vs. 3.5%, P = 0.004) rates but not for the OS (100% vs. 99.2%, P = 0.487) rate. Similar results were obtained after excluding patients given trastuzumab.

CONCLUSIONS

The decision to use trastuzumab in HER2-amplified pT1ab tumors must balance their poor outcome against intrinsic financial limitations in LMCs. Patient selection criteria needs fine-tuning, and resource-sensitive regimens must be explored.

Age and associated fibrocystic changes are prognostically significant in patients with small node-negative (T1a,bN0) invasive breast cancer

Some patients with small (≤1.0 cm) node-negative (T1a,bN0) invasive breast cancer (IBC) who undergo only local therapy experience recurrences. There is limited information on prognostic factors in these patients. We sought to identify prognostic factors associated with disease-free survival (DFS) and overall survival (OS) in patients with T1a,bN0 IBC. Histologic sections from 273 T1a,bN0 IBC patients treated at M. D. Anderson Cancer Center (MDACC) between 1980 and 1999 were reviewed. Microscopic tumor size; multifocality; histologic type, grade of tumor; presence, type, grade of associated ductal carcinoma in situ (DCIS); presence of fibrocystic changes (FCC) with/without atypia; and lymphovascular invasion were identified. The Kaplan-Meier method was used to evaluate DFS and OS. Median patient age was 58 years, median follow-up period was 10.8 years, and median tumor size was 0.8 cm. Multifocal disease was identified in 26% of cases. At 10 years, the DFS and OS rates were 91% and 88%, respectively. Twenty-one percent of patients had extensive (>50%), and 30% had grade 3 DCIS. Nonproliferative FCC and proliferative FCC with/without atypia were present in 80%, 36%, and 38% of patients, respectively. In univariate analysis, age at diagnosis (p < 0.0001), grade (p = 0.015), and percent (p = 0.046) of DCIS were significantly associated with DFS; presence of FCC was associated with longer DFS and OS. In multivariable models, age and presence of FCC remained significantly associated with survival. Age at diagnosis and associated FCC are significant factors in predicting recurrence in patients with T1a,bN0 IBC. Adjuvant systemic therapy should be discussed with and considered for young patients with T1a,bN0 IBC.

Can we identify the group of small invasive (T1a,b) breast cancers with minimal risk of axillary lymph node involvement? A pathohistological and DNA flow cytometric study

The goal of this study was to identify a group of small (≤1cm) breast cancers (T1a,b) with a particularly low probability of axillary lymph node metastases, where routine axillary staging may be unnecessary. We retrospectively analyzed 152 T1a,b breast carcinomas with axillary dissection surgically removed at Clinical Hospital Center Split (Croatia) in the period from 1997 to 2006. The analysis included 40 T1a,b cancers with, and 112 T1a,b cancers without axillary lymph node metastases. The basic morphological features of cancers were investigated histologically, while hormone receptors and HER2/neu were investigated immunohistochemically with an additional CISH analysis of HER2/neu 2+ cases. The ploidy and S-phase fraction were determined by DNA flow cytometry. The association of the investigated features with the likelihood of axillary lymph node metastases was analyzed by univariate and multivariate analysis. The univariate analysis showed that lymph node metastases were associated with tumor size (T1a/T1b; p=0.026), histological type (ductal/non-ductal; p=0.014), lymphovascular invasion (p<0.001), HER2/neu expression (p=0.04), ploidy (p=0.027), and combined values of ploidy and S-phase fraction (p=0.025). The lymphovascular invasion was the only independent factor associated with axillary nodal metastases (p=0.01). In the group of T1a,b cancers without lymphovascular invasion, HER2/neu expression (p=0.021) and combined values of ploidy and S-phase fraction (p=0.016) were independent factors associated with axillary lymph node metastases. This study showed that diploid T1a,b cancers with low S-phase fraction, which are also without lymphovascular invasion and HER2/neu amplification, represented the group of cancers with a low probability of axillary lymph node metastases.

Management of small HER2-positive breast cancers

Trastuzumab has revolutionised the treatment of HER2-positive early-stage breast cancer and is now standard of care in combination with chemotherapy for patients with tumours larger than 1 cm. However, 5 years after publication of the landmark trials establishing the efficacy of the drug, the management of small (≤1 cm), HER2-positive tumours remains difficult. Most small breast cancers have a good prognosis and adjuvant chemotherapy is not routinely recommended. However, retrospective data suggest that some small HER2-positive cancers might have a worse clinical outcome than others. This notion raises the key clinical question of whether patients with small HER2-positive cancers should be offered adjuvant trastuzumab and chemotherapy. The pivotal adjuvant trastuzumab trials did not include patients with tumours smaller than 1 cm, but a subset analysis of one trial showed that patients with tumours 1-2 cm in size derived at least as much clinical benefit from 1 year of adjuvant trastuzumab as did the overall cohort. Clinicians face the dilemma of whether the potential reduction in risk of recurrence in this patient group warrants the toxic effects and risks of adjuvant chemotherapy and trastuzumab. In this review, we discuss the evidence for prognosis of small HER2-positive cancers, and for possible benefit from adjuvant trastuzumab. We suggest potential treatment strategies and clinical trial designs to address this important issue. On the basis of present evidence, we recommend that the benefits and risks of adjuvant trastuzumab should be discussed with patients with small, HER2-positive breast cancer.

A risk stratification by hormonal receptors (ER, PgR) and HER-2 status in small (< or = 1 cm) invasive breast cancer: who might be possible candidates for adjuvant treatment?

As the use of screening mammography expands, the proportion of invasive breast cancer > or = 1 cm is increasing. The aims of this study were: (1) to identify risk factors for systemic metastases in patients with > or = 1 cm invasive breast cancer and (2) to investigate the patient groups at the greatest risk for metastases with such small tumors. Data were collected retrospectively from the breast cancer registry of our institution for patients with invasive breast cancer from October 1994 to December 2004. Of 4,036 patients who received curative breast cancer surgery, we identified 427 patients who had T1a or T1b breast cancer excluding 39 patients who received neoadjuvant chemotherapy. Ipsilateral axillary lymph node involvement was found in 13% (57/427) of patients at the time of surgery. A multivariate analysis was conducted in 370 (T1aN0, T1bN0) patients without lymph node involvement. In a Cox-regression model, HER-2 positive and triple negative (TN) groups were identified as independent risk factors to predict distant relapse-free survival (DRFS) [Hazard ratio (HR) 8.8, P = 0.003 for HER-2 positive group; HR 5.1, P = 0.026 for TN group] in T1bN0 tumors. Statistical significance was not maintained when the analysis was limited to T1aN0 tumors. Even though T1aN0 and T1bN0 tumors have a relatively low risk of systemic failure, antiHER-2-directed therapy for HER-2 group and new innovative adjuvant systemic treatment for TNBC patients with T1bN0 tumors should be considered. Prospective adjuvant trials are warranted in these subgroups of patients.

Lymphovascular invasion and lobular histology are associated with increased incidence of isolated tumor cells in sentinel lymph nodes from early-stage breast cancer patients

BACKGROUND

Isolated tumor cells (ITC) are more likely to be identified when serial sectioning and immunohistochemical staining are used to evaluate sentinel lymph nodes (SLN). Our goal was to identify clinicopathologic features associated with ITC in patients undergoing sentinel lymph node dissection (SLND).

METHODS

We reviewed clinicopathologic data for 3557 patients with no clinical evidence of lymph node metastases undergoing SLND between November 1993 and March 2007. Patients were staged according to the 6th edition of the American Joint Committee on Cancer staging system, with metastasis <or=.2 mm classified as ITC.

RESULTS

A SLN was identified in 3475 patients (97.7%), including 2518 (72.4%) with negative nodes and 169 (4.9%) with ITC. A statistically significant association existed between lobular histology and the identification of ITC; 13.6% of patients with ITC had lobular histology versus 7.3% of patients with a negative SLN (P = .003). The presence of lymphovascular invasion (LVI) was also associated with ITC; 18.3% of patients with ITC had LVI in the primary tumor versus 8.5% of patients with a negative SLN (P < .001). No difference existed between patients with and without ITC with respect to T stage, grade, estrogen receptor, progesterone receptor, HER2/neu status, or biopsy method.

CONCLUSION

The association between ITC and LVI, a known predictor of poor outcome, suggests ITC may have clinical relevance. The relationship between lobular histology and ITC is consistent with the known pattern of lobular metastases, which frequently present as small foci requiring immunohistochemistry for detection. Longer follow-up is needed to determine whether ITC have prognostic significance.

Sentinel lymph node biopsy in women with pT1a or "microinvasive" breast cancer

The role of sentinel lymph node biopsy (SLNB) in pT1a and "microinvasive" breast cancer has not been extensively studied. We report our experience with SLNB in patients with "minimal" breast cancer to determine the incidence and type of SLN metastases, and to study the potential impact on their surgical or oncological management. Among some 3387 women operated upon for primary breast cancer who underwent sentinel lymph node biopsy at nine institutions participating in the Rome Breast Cancer Study Group, 251 were staged pT1a or pT1mic (7.4%). There were 13 cases of sentinel lymph node metastases identified in this group of patients (5.2%), seven macrometastases and six micrometastases. Additionally, ITC were diagnosed by immunohistochemistry in four cases (1.6%). The incidence of SLN metastases was 7/174 (4%) and 6/77 (7.8%) in patients with pT1a and pT1mic tumors, respectively (p=0.2). Age and histological grade were predictive factors for SLN metastases. Chemotherapy was seldom directed by axillary node status (8/38 patients). As the incidence of SLN metastases in these patients is very small, particularly in the pT1a group, the indications for even a minimally invasive procedure, such as sentinel lymph node biopsy, should be probably individualized.

Pathobiology of small invasive breast cancers without metastases (T1a/b, N0, M0): National Surgical Adjuvant Breast and Bowel Project (NSABP) protocol B-21

BACKGROUND

Uncertainties continue to exist concerning the outcomes and management of small (T1a/b N0 M0) invasive breast cancers.

METHODS

A central pathology review was performed of 638 such lesions from National Surgical Adjuvant Breast and Bowel Project (NSABP) clinical trial B-21.

RESULTS

Univariate analysis revealed a high risk for ipsilateral breast tumor recurrence with tumors exhibiting a ductal carcinoma in situ component or poor nuclear grade. The converse (protective effect) was found with tumors arising in radial scars, those of tubular histologic type, and those with moderate/marked tumor stroma. The correlations were generally similar for disease-free survival. However, only nuclear grade was found to be independently significant for both of these outcomes. Only lymphatic tumor extension was univariately and multivariately significant for overall survival.

CONCLUSIONS

The long-term results of follow-up (median, 11.2 years) from the current trial continue to support the need for local breast irradiation and adjuvant therapy in the management of patients with these small cancers.

Overall survival and cause-specific mortality of patients with stage T1a,bN0M0 breast carcinoma

PURPOSE

With mammographic screening, the frequency of diagnosis of stage T1a,bN0M0 breast cancer has increased. Prognosis after locoregional therapy and benefit from adjuvant systemic therapy are poorly defined. We reviewed T1a,bN0M0 breast cancer cases registered in the Surveillance, Epidemiology, and End Results (SEER) Program to investigate the impact of prognostic factors on breast cancer-specific (BCSM) and non-breast cancer-related mortality.

METHODS

We identified T1a,bN0M0 breast cancer cases registered in the SEER Program from 1988 to 2001, and used the Kaplan-Meier product limit method to describe overall survival (OS). We estimated the probabilities of death resulting from breast cancer and from other causes, and analyzed associations of patient and tumor characteristics with OS, BCSM, and non-breast cancer-related mortality using the log-rank test, Cox proportional hazards models, and a competing-risk model. We constructed nomograms to assist physicians in adjuvant therapy decision making.

RESULTS

We identified 51,246 T1a,bN0M0 cases. Median follow-up was 64 months (range, 1 to 167 months). Median age at diagnosis was 65 years (range, 20 to 101 years). Ten-year probabilities of all-cause mortality and BCSM were 24% and 4%, respectively. Characteristics associated with increased probability of BCSM included age younger than 50 years at diagnosis, high tumor grade, estrogen receptor-negative status, progesterone receptor-negative status, and fewer than six nodes removed at axillary dissection. The constructed nomograms allow a comparison of predicted breast cancer-specific survival and non-breast cancer-specific survival in individual patients.

CONCLUSION

Overall, the prognosis of patients with T1a,bN0M0 breast cancer is excellent. However, subgroups of patients who are at higher risk of BCSM and who should be considered for adjuvant systemic therapy can be identified.

Treatment trends and factors associated with survival in T1aN0 and T1bN0 breast cancer patients

BACKGROUND

Breast conservation therapy (BCT) and adjuvant hormonal therapy for estrogen-receptor positive breast cancers have become standard of care. Our objectives were to evaluate trends in the surgical management and adjuvant therapy for early-stage breast cancer and to identify factors predicting survival.

METHODS

Using the National Cancer Data Base (NCDB), patients with node-negative breast cancers less than 1 cm (T1aN0M0 and T1bN0M0) from 1993-2004 were identified. The time periods of 1993-1994, 1998-1999, and 2003-2004 were compared to analyze trends in surgical management and adjuvant therapy. Cox Proportional Hazards modeling was used to examine factors predicting survival.

RESULTS

Overall, 123,212 cases of T1aN0M0 or T1bN0M0 breast cancer were identified. The use of breast conservation surgery increased from 61.3% in 1993/1994 to 78.3% in 2003/2004 with a concomitant decrease in the use of mastectomy. The use of radiation therapy also increased from 51.9% in 1993/1994 to 62.0% in 2003/2004. Adjuvant hormonal therapy administration rose sharply from 26.7% in 1993/1994 to 44.7% in 2003/2004. After adjusting for potential confounders, the difference in 5-year survival rates for T1a (94.3%) and T1b (93.1%) tumors was marginal (P = .04). Age, grade, size, and failure of BCS patients to receive radiation therapy and hormonal therapy were independent predictors of a higher likelihood of death.

CONCLUSIONS

BCS utilization increased over time, but mastectomy rates may still be considered high given the small size of tumors in this cohort and the percent of patients eligible for BCT. The use of hormonal therapy increased significantly over the past decade. Further investigation into patient and physician factors affecting treatment choices is needed if BCT and hormonal therapy utilization is to increase.

Prognosis and Management of Patients With Node-Negative Invasive Breast Carcinoma That Is 1 cm or Smaller in Size (stage 1; T1a,bN0M0): A Review of the Literature

Purpose

Mammographic screening has led to an increase in the number of small, node-negative breast cancers being diagnosed. Node-negative breast cancers that are ≤ 1 cm are stage T1a,bN0M0. Controversy surrounds the prognosis of these patients with locoregional therapy only and the need for adjuvant systemic therapy.

Methods

We performed a comprehensive review of the literature describing outcome and prognostic factors in stage T1a,bN0M0 breast cancer. We also reviewed current guidelines for systemic therapy in these patients.

Results

Early studies reported 10-year relapse-free survival (RFS) rates higher than 90% without adjuvant systemic therapy, but some more recent data suggest inferior outcomes. High tumor grade is the most consistent factor associated with poor prognosis. Other adverse prognostic factors are younger age, lymphovascular invasion (LVI), high Ki-67, and larger tumors within the T1a,b subgroup. Patients with high-grade tumors and/or LVI may have 10-year RFS rates of less than 75% in the absence of systemic therapy. The prognostic significance of hormone receptor status is unclear. Current guidelines for the systemic management of early-stage breast cancer differ when applied to stage T1a,bN0M0, reflecting the controversial nature of the issue.

Conclusion

Adjuvant systemic therapy is advisable for most patients with stage T1a,bN0M0 breast cancer who have grade 3 tumors and/or LVI. Other T1a,bN0M0 cases should be considered for systemic therapy based on clinicopathologic factors with known prognostic significance and assessment of the risk-benefit ratio. More reliable tools are needed to assess the prognosis of patients with stage T1a,bN0M0 breast cancer and their potential to benefit from specific therapeutic agents.

Minimal and small size invasive breast cancer with no axillary lymph node involvement: the need for tailored adjuvant therapies

BACKGROUND

Prognosis of patients with node-negative disease and tumor size <1 cm is a matter of controversy. While data exist to clearly correlate small tumor size to better prognosis, the fact that very small breast cancers may express biological markers of dire prognosis leads many to ignore small tumor size during treatment decision-making.

PATIENTS AND METHODS

Data from 425 patients classified as having node-negative pT1mic, pT1a or pT1b after surgery (from April 1997 to December 2001) at the European Institute of Oncology, were analyzed to be described as disease-free according to prognostic variables including: Ki-67 (<20% versus > or =20% of the cells), ER (absent versus positive > or =1% of the cells), PgR (absent versus positive > or =1% of the cells), grade, overexpression or amplification of HER2/neu, presence of peritumoral vascular invasion and age (by decade). The median follow-up for this cohort of patients was 43 months.

RESULTS

No local or distant relapse was observed for patients with pT1mic breast cancer; 4-year disease-free survival for pT1a and pT1b was 97.0% and 97.6%, respectively. In both univariate and multivariate analyses the most relevant prognostic factor for this low-risk population was Ki-67 labeling. The 4-year disease-free survival was 99.2% for tumors with low Ki-67 and 93.3% for tumors with high Ki-67 (> or =20%) labeling. The hazard ratio (HR) for patients with high Ki-67 was 12.9 (95% CI 1.5-112.0, P=0.02).

CONCLUSIONS

Within the first 4 years, microinvasive breast cancer parallels ductal carcinoma in situ (DCIS) rather than invasive carcinoma. Costs and benefits of adjuvant therapy should be accurately weighted in these patients. Patients with pT1a and pT1b, node-negative disease have a limited but substantial risk of recurrence and therefore adjuvant therapy, according to endocrine responsiveness of the tumor and patient preference, should continue to be offered as a reasonable treatment option.

Management of T1a Breast Cancer

Identification of early-stage breast cancers has increased over the past 2 decades primarily because of mammographic screening. The general guidelines to management of breast cancer may not apply to the smallest of these tumors, as their metastatic potential may be smaller than larger tumors. Tumors < 5 mm (T1a) carry an excellent prognosis, despite a variety of treatment approaches. However, some patients' cancer returns. There appear to be some histologic features that can predict a higher risk of axillary metastases, and therefore, a higher risk of distant metastases. Controversy exists over the extent of treatment, as to whether less than conventional treatment, such as mastectomy, axillary evaluation, and breast-conserving surgery and radiation, can be done. T1a lesions associated with extensive ductal carcinoma in situ and T1a lesions in young patients should be treated with caution if less than conventional breast treatment is to be considered. In older patients with good histologic features, axillary assessment may not be necessary. Very wide excision alone may be appropriate for some patients, but partial breast irradiation is under study and may provide a reasonable compromise. Systemic therapy for node-negative patients is not recommended. Recurrences within the breast occur later in early-stage breast cancers than with extensive-stage breast cancers, requiring annual imaging and evaluation for many years.

Small invasive breast carcinomas in Taiwanese women

BACKGROUND

Female Taiwanese breast cancer patients are younger than their Western counterparts. This study examined the predictors of axillary lymph node metastases in Taiwanese women with T1 breast cancer.

METHODS

Data from 394 Taiwanese women with T1 invasive breast carcinoma were retrospectively reviewed.

RESULTS

The data contained 6 T1a, 51 T1b, and 337 T1c breast tumors. The patients' ages ranged from 23 to 82 years (mean +/- SD, 48.2 +/- 11.4 years; median, 46.4 years). Axillary nodal metastases were present in 38.3% of the patients (16.7% in T1a, 35.3% in T1b, and 39.2% in T1c tumors). The patients with nodal metastases had significantly greater body weights and S-phase fractions than those without nodal metastases. Univariate analysis revealed that unfavorable pathology, lymphovascular invasion, S-phase fraction >7%, and nondiploid DNA ploidy were significantly associated with lymph node metastases. Lymphovascular invasion was the only significant variable as the independent predictor in the multiple logistic regression analysis. In the Cox proportional hazards regression analysis, axillary nodal status and lymphovascular invasion were significantly associated with survival.

CONCLUSIONS

Taiwanese women with small breast cancer displayed a relatively higher incidence of axillary lymph node metastases than Western women. Axillary lymph node dissection or sentinel lymph node biopsy should be conducted on Taiwanese patients with small invasive breast carcinomas, particularly when risk factors exist.

Will we need lymph node dissection at all in the future?

Traditionally in the treatment of primary breast cancer, axillary lymph node dissection (ALND) plays an important role. However, a substantial and increasing percentage of patients appear to have no nodal involvement and have been subjected to ALND unnecessarily. The first reason to perform an ALND is axillary nodal staging. After reviewing the literature, it can be concluded that in clinically node-negative patients an adequately conducted lymphatic mapping by sentinel node procedure is equal to ALND for this purpose. The second reason to perform an ALND is to establish the extent of nodal involvement, which might have an impact on adjuvant treatment recommendations. However, there is no evidence available that patients with extensive nodal involvement (= 4 positive nodes) benefit more from adjuvant systemic treatment (either standard or high dose) in terms of reduction of odds of recurrence and mortality compared to patients with limited nodal involvement and optimally administered so-called standard adjuvant treatment. The third reason to perform an ALND is to ensure axillary tumor control. Reviewing the different treatment options, it can be concluded that in clinically node-negative patients axillary control after axillary radiotherapy appears to be similar to axillary control after ALND. In clinically overt axillary involvement, ALND (with or without adjuvant radiotherapy) may result in an improved regional control. In the near future, ALND will not be the standard of care but will be reserved for those patients with proven axillary lymph node involvement. In microscopic disease, radiotherapy may be an alternative with equal control and less morbidity.