Disease Extent ≥4 cm Is a Prognostic Marker of Local Recurrence in T1-2 Breast Cancer

The subgross morphology of breast carcinomas: a single-institution series of 2033 consecutive cases documented in large-format histology slides

A large-format histology technique represents the most convenient method for documenting and assessing the subgross morphological prognostic parameters of breast cancer (i.e., the distribution of the tumor's invasive and in situ components, disease extent, and tumor size), especially when used in conjunction with systematic radiological-pathological correlation. Here we report a consecutive series of 2033 breast carcinomas operated on in Dalarna, Sweden, with a particular focus on these subgross parameters. We separately analyzed the distributions of the in situ and invasive components of the tumors and then combined these into an aggregate pattern when both components were present. We found that 40% of breast carcinomas had a simple (unifocal) subgross morphology, while 60% had a complex morphology presenting with multifocal or diffuse components. Extensive tumors (occupying a total volume of breast tissue with the greatest dimension being ≥ 40 mm) were more common in complex cases, occurring in 66% of multifocal cases and 88% of diffuse cases, compared with only 5% of unifocal cases. Compared with luminal A-like tumors, HER2-expressing tumors exhibited a significantly larger extent. Triple-negative and basal-like carcinomas tended to have a larger tumor size (based on the largest dimension of the largest invasive focus). In this report, we discuss the prognostic impact of these parameters and the necessity of their correct assessment in the diagnostic routine.

Early (<10 mm) HER2-Positive Invasive Breast Carcinomas are Associated with Extensive Diffuse High-Grade DCIS: Implications for Preoperative Mapping, Extent of Surgical Intervention, and Disease-Free Survival

BACKGROUND

The few publications on <10-mm invasive breast carcinomas have reported worse outcomes for women with human epidermal growth factor receptor 2 (HER2)-positive cancer compared with HER2-negative cases and indicated that the high risk of recurrence in HER2-positive cases is related to the high grade, hormone receptor negativity, and high proliferation index of the invasive tumor component.

METHODS

We studied the subgross morphology of such tumors in a consecutive series of 203 cases documented in large-format histology slides and worked up with detailed radiological-pathological correlation.

RESULTS

The invasive component was associated with a diffuse in situ component in 78 % of the HER2-positive and 26 % of HER2-negative tumors <10 mm in size (odds ratio [OR], 11.3936; P < .0001). The in situ component was of high grade in 75 % of HER2-positive and 9 % of HER2-negative cases (OR, 29.6000; P < .0001). Significant associations were also found between the HER2 positivity of the invasive component and diffuse combined lesion distribution (P > .0001), invasive tumor grade 3 (P = .0004), presence of vascular invasion (P = .0026), extensive disease (P = .0170), "not special" (ductal) histological tumor type (P = .0302), estrogen receptor negativity (OR, 7.8846; P < .0001), and high Ki67 proliferation index (OR, 5.0000; P = .0007). The HER2-positive tumors tended to be multifocal (OR, 2.000) and lymph node-positive (OR, 3.0147), but the tendency was not statistically significant.

CONCLUSIONS

The vast majority of <10-mm HER2-positive breast carcinomas exhibited a high-grade, diffuse, and extensive in situ component, which may explain the high risk of recurrence among these tumors.

The role of large-format histopathology in assessing subgross morphological prognostic parameters: a single institution report of 1000 consecutive breast cancer cases

Breast cancer subgross morphological parameters (disease extent, lesion distribution, and tumor size) provide significant prognostic information and guide therapeutic decisions. Modern multimodality radiological imaging can determine these parameters with increasing accuracy in most patients. Large-format histopathology preserves the spatial relationship of the tumor components and their relationship to the resection margins and has clear advantages over traditional routine pathology techniques. We report a series of 1000 consecutive breast cancer cases worked up with large-format histology with detailed radiological-pathological correlation. We confirmed that breast carcinomas often exhibit complex subgross morphology in both early and advanced stages. Half of the cases were extensive tumors and occupied a tissue space ≥40 mm in its largest dimension. Because both in situ and invasive tumor components may exhibit unifocal, multifocal, and diffuse lesion distribution, 17 different breast cancer growth patterns can be observed. Combining in situ and invasive tumor components, most cases fall into three aggregate growth patterns: unifocal (36%), multifocal (35%), and diffuse (28%). Large-format histology categories of tumor size and disease extent were concordant with radiological measurements in approximately 80% of the cases. Noncalcified, low-grade in situ foci, and invasive tumor foci <5 mm were the most frequent causes of discrepant findings.

Comparison of the subgross distribution of the lesions in invasive ductal and lobular carcinomas of the breast: a large-format histology study

To compare the lesion distribution and the extent of the disease in ductal and lobular carcinomas of the breast, we studied 586 ductal and 133 lobular consecutive cancers. All cases were documented on large-format histology slides. The invasive component of ductal carcinomas was unifocal in 63.3% (371/586), multifocal in 35.5% (208/586), and diffuse in 1.2% (7/586) of the cases. The corresponding figures in the lobular group were 27.8% (37/133), 45.9% (61/586), and 26.3% (35/133), respectively. When the distribution of the in situ and invasive component in the same tumors was combined to give an aggregate pattern, the ductal carcinomas were unifocal in 41.6% (244/586), multifocal in 31.6% (185/586), and diffuse in 26.8% (157/586) of the cases. The corresponding figures in the lobular category were 15.0% (20/133), 54.2% (72/133), and 30.8% (41/133), respectively. Ductal cancers were extensive in 45.7% (268/586), lobular in 65.4% (87/133) of the cases. All these differences were statistically highly significant (P < 0.0001). While the histological tumor type itself (ductal versus lobular) did not influence the lymph node status, multifocal and diffuse distribution of the lesions were associated with significantly increased risk of lymph node metastases in both ductal and lobular cancers.