Complexities and challenges in the pathologic assessment of size (T) of invasive breast carcinoma

Quality of Anatomic Staging of Breast Carcinoma in Hospitals in the United States, With Focus on Measurement of Tumor Dimension

OBJECTIVES

We investigated the accuracy of clinical breast carcinoma anatomic staging and the greatest tumor dimension measurements.

METHODS

We compared clinical stage and greatest dimension values with the pathologic reference standard values using 57,747 cases from the 2016 US National Cancer Institute Surveillance, Epidemiology, and End Results program who were treated by surgical resection without prior neoadjuvant therapy.

RESULTS

Agreement for clinical vs pathologic anatomic TNM group stage, overall, is 74.3% ± 0.4%. Lymph node N staging overall agrees very well (85.1% ± 0.4%). Based on tumor dimension and location, T staging has an agreement of only 64.2% ± 0.4%, worsening to 55% without carcinoma in situ (Tis) cases. In approximately 25% of cases, pathologic T stage is higher than clinical T stage. The mean difference in the greatest dimension is 1.36 ± 9.59 mm with pathologic values being generally larger than clinical values; pathologic and clinical measurements correlate well. T-stage disagreement is associated with histology, tumor grade, tumor size, N stage, patient age, periodic biases in tumor size measurements, and overuse of family T-stage categories. Pathologic measurement biases include rounding and specimen-slicing intervals.

CONCLUSIONS

Clinical and pathologic T-staging values agree only moderately. Pathologists face challenges in increasing the precision of gross tumor measurements, with the goal of improving the accuracy of clinical T staging and measurement.

Tumor Size on Microscopy, CT, and MRI Assessments Versus Pathologic Gross Specimen Analysis of Pancreatic Neuroendocrine Tumors

OBJECTIVE. The purpose of the present study was to assess the consistency of measurements of pancreatic neuroendocrine tumor (PNET) tumor size obtained using pre-operative imaging, pathologic gross specimen analysis, and microscopic examination of large pathologic sections; evaluate the impact of differences in pathologic and radiologic measurements of size on T categorization; and investigate the exact relationships among tumor size measurements obtained from microscopic analysis, CT, MRI, and pathologic gross specimen analysis. MATERIALS AND METHODS. We enrolled 64 patients with pathologically confirmed PNETs who underwent radiologic examination between December 2016 and September 2019. Tumor sizes were measured by CT, MRI, pathologic gross specimen analysis, and microscopic examination. The relationship between the tumor sizes calculated by MRI and microscopy was analyzed using univariate and multivariate logistic regression models. RESULTS. The measurements of tumor sizes calculated by pathologic and radiologic assessments and CT and MRI assessments showed good concordance, but measurements calculated by microscopic analysis and other methods showed poor concordance. When T categories from pathologic gross specimen analysis were considered the reference, alterations in T category were found in the microscopic assessments of 12 of 64 patients (18.75%), CT assessments of 15 of 64 patients (23.44%), and MRI assessments of 13 of 64 patients (20.31%). In the fully adjusted model, microscopic size (β, 1.05; 95% CI, 0.98-1.12; p < .001), CT size (β, 0.90; 95% CI, 0.78-1.02; p < .001), and MRI size (β, 0.92; 95% CI, 0.81-1.04; p < .001) were significantly correlated with gross tumor size. CONCLUSION. Tumor sizes measured by microscopy, CT, and MRI were significantly associated with the gross size of PNETs. This finding provides physicians with new tools for rapid identification of gross tumor size.

Measuring Invasive Breast Carcinoma on Core Biopsy: Is it Necessary?: An Analysis of Ultrasound, Mammotome, and Magnetic Resonance Imaging-Guided Core Biopsies

CONTEXT.—

Pathologic tumor size is significant in the treatment of breast carcinoma and is routinely measured on excision.

OBJECTIVE.—

To analyze the need for measuring size of invasive mammary carcinoma on biopsy.

DESIGN.—

Nine hundred twenty-two cases of invasive carcinoma whose size was measured (greatest linear measurement) on biopsy and excision was correlated, including imaging when available (110 cases).

RESULTS.—

Patient mean age was 62 years. Most (90%; 830 of 922) carcinomas were ductal and sampled by ultrasound and graded as follows: well, 13% (113 of 922); moderately, 58% (532 of 922), and poorly differentiated, 28% (258 of 922); 19 microinvasive not graded. Tumor mean size was 7.5 mm on biopsy and 14.4 mm on excision. Biopsy modality was as follows: ultrasound, 7.8 mm (92%, 844 of 922); mammotome, 3.3 mm (7%, 65 of 922); and magnetic resonance imaging, 5.9 mm (1%, 13 of 922). Size comparison on biopsy versus excision was biopsy > excision: 8% (72 of 922), biopsy = excision: 10% (95 of 922), and biopsy < excision: 82% (755 of 922). Half (36 of 72) of the biopsy > excision tumors were less than 5 mm, 96% (726 of 755) of biopsy < excision tumors were greater than 5 mm, while those equal on both were predominantly (88%, 84 of 95) less than 10 mm, 20% (19 of 95) of which were microinvasive. Stage changed in 600 cases, staging based on excision in 581 (63%), and staging based on biopsy in 19 (2%). Radiologic-pathologic correlation (n = 110) showed perfect concordance in 11 (10%), 83 (75%) were ±1 to 2 mm and 16 (15%) were ± more than 3 mm. Difference between the biopsy and excision ranged from a lower limit of 1.3 mm for T1a tumors to 18 mm for T2.

CONCLUSIONS.—

While most carcinomas are larger on excision, 18% (167 of 922) are larger or equal on biopsy. Factors predictive of biopsy > excision tumors include stage 1 tumors (P < .001), especially less than 5 mm, and sampled by mammotome. We recommend measuring invasive carcinoma on biopsy and excision.

Factors affecting the concordance of radiologic and pathologic tumor size in breast carcinoma

Background

Radiologic assessment of tumor size is an integral part of the work-up for breast carcinoma. With improved radiologic equipment, surgical decision relies profoundly upon radiologic/clinical stage. We wanted to see the concordance between radiologic and pathologic tumor size to infer how accurate radiologic/clinical staging is.

Materials and methods

The surgical pathology and ultrasonography reports of patients with breast carcinoma were reviewed. Data were collected for 406 cases. Concordance was defined as a size difference within ±2 mm.

Results

The difference between radiologic and pathologic tumor size was within ±2 mm in 40.4% cases. The mean radiologic size was 1.73 ± 1.06 cm. The mean pathologic size was 1.84 ± 1.24 cm. A paired t-test showed a significant mean difference between radiologic and pathologic measurements (0.12 ± 1.03 cm, p = 0.03). Despite the size difference, stage classification was the same in 59.9% of cases. Radiologic size overestimated stage in 14.5% of cases and underestimated stage in 25.6% of cases. The concordance rate was significantly higher for tumors ≤2 cm (pT1) (51.1%) as compared to those greater than 2 cm (≥pT2) (19.7%) (p < 0.0001). Significantly more lumpectomy specimens (47.5%) had concordance when compared to mastectomy specimens (29.8%) (p < 0.0001). Invasive ductal carcinoma had better concordance compared to other tumors (p = 0.02).

Conclusion

Mean pathologic tumor size was significantly different from mean radiologic tumor size. Concordance was in just over 40% of cases and the stage classification was the same in about 60% of cases only. Therefore, surgical decision of lumpectomy versus mastectomy based on radiologic tumor size may not always be accurate.

Tumor Size in Breast Carcinoma: Gross Measurement Is Important!

Introduction. The staging of breast carcinoma is mainly dependent on tumor size and lymph node status. Small increments in tumor size upstage the patient. An accurate determination of the tumor size is therefore critically important. Although the final staging is based on microscopic size, pathologists rely on gross measurements in a considerable number of cases. Methods. We investigated the concordance between gross and microscopic measurements of breast carcinoma as well as factors affecting this concordance. This study is a retrospective review of surgical pathology reports of invasive breast carcinomas. Data were collected for 411 cases. Concordance was defined as a size difference within ±2 mm. Results. Gross and microscopic sizes were identical in 33.1% of cases. Gross and microscopic size difference was within ±2 mm in 56% of cases. Despite the size difference, stage classification ended up being the same in 68.6% of cases. Tumor stage was over estimated by gross measurement in 17.0% of cases and underestimated in 14.4% of cases. The concordance was significantly higher for those tumors in which final pathologic tumor (pT) size was greater than 2 cm (≥pT2) as compared with those less than or equal to 2 cm (≤pT1; P < .0001). A higher proportion of mastectomy specimens (61.4%) were concordant as compared with lumpectomy specimens (52.1%). Conclusion. Gross and microscopic tumor sizes were concordant in 56% of cases. Stage classification based on gross and microscopic tumor size was different in nearly one third (31.4%) of cases. Gross tumor size is critically important in accurate staging at least in cases where tumor size cannot be confirmed microscopically.

Three-Dimensional Assessment of Automated Breast Volume Scanner Compared with Handheld Ultrasound in Pre-Operative Breast Invasive Ductal Carcinomas: A Pilot Study of 51 Cases

The aim of the work described here was to compare the accuracy of conventional handheld ultrasound (HHUS) with that of an automated breast volume scanner (ABVS) in 3-D assessment of pre-operative invasive ductal carcinomas. HHUS and ABVS were used in 51 patients to obtain the largest tumor diameter, tumor volume and tumor surface area. The volumetric measurement was also obtained from ABVS data with medical software. With tumor size and volume on pathology as the gold standard, Bland-Altman analysis was used to compare variability. Correlation coefficients and receiver operating characteristic curves were established for all measurements for T2 classification. The correlation coefficients of all ABVS measurements were stronger than those of HHUS measurements, with the ABVS volumetric measurement significantly different with a higher accuracy of 88.24% (45/51) and predicting T-classification with higher area under the receiver operating characteristic curves (0.936). Therefore, 3-D measurements provide stronger correlations with pathology in tumor size measurement. However, more clinical trials are needed to confirm our findings.