Minimally Invasive Complete Response Assessment of the Breast After Neoadjuvant Systemic Therapy for Early Breast Cancer (MICRA trial): Interim Analysis of a Multicenter Observational Cohort Study

BACKGROUND

The added value of surgery in breast cancer patients with pathological complete response (pCR) after neoadjuvant systemic therapy (NST) is uncertain. The accuracy of imaging identifying pCR for omission of surgery, however, is insufficient. We investigated the accuracy of ultrasound-guided biopsies identifying breast pCR (ypT0) after NST in patients with radiological partial (rPR) or complete response (rCR) on MRI.

METHODS

We performed a multicenter, prospective single-arm study in three Dutch hospitals. Patients with T1-4(N0 or N +) breast cancer with MRI rPR and enhancement ≤ 2.0 cm or MRI rCR after NST were enrolled. Eight ultrasound-guided 14-G core biopsies were obtained in the operating room before surgery close to the marker placed centrally in the tumor area at diagnosis (no attempt was made to remove the marker), and compared with the surgical specimen of the breast. Primary outcome was the false-negative rate (FNR).

RESULTS

Between April 2016 and June 2019, 202 patients fulfilled eligibility criteria. Pre-surgical biopsies were obtained in 167 patients, of whom 136 had rCR and 31 had rPR on MRI. Forty-three (26%) tumors were hormone receptor (HR)-positive/HER2-negative, 64 (38%) were HER2-positive, and 60 (36%) were triple-negative. Eighty-nine patients had pCR (53%; 95% CI 45-61) and 78 had residual disease. Biopsies were false-negative in 29 (37%; 95% CI 27-49) of 78 patients. The multivariable associated with false-negative biopsies was rCR (FNR 47%; OR 9.81, 95% CI 1.72-55.89; p = 0.01); a trend was observed for HR-negative tumors (FNR 71% in HER2-positive and 55% in triple-negative tumors; OR 4.55, 95% CI 0.95-21.73; p = 0.058) and smaller pathological lesions (6 mm vs 15 mm; OR 0.93, 95% CI 0.87-1.00; p = 0.051).

CONCLUSION

The MICRA trial showed that ultrasound-guided core biopsies are not accurate enough to identify breast pCR in patients with good response on MRI after NST. Therefore, breast surgery cannot safely be omitted relying on the results of core biopsies in these patients.

Reliability of preoperative breast biopsies showing ductal carcinoma in situ and implications for non-operative treatment: a cohort study

PURPOSE

The future of non-operative management of DCIS relies on distinguishing lesions requiring treatment from those needing only active surveillance. More accurate preoperative staging and grading of DCIS would be helpful. We identified determinants of upstaging preoperative breast biopsies showing ductal carcinoma in situ (DCIS) to invasive breast cancer (IBC), or of upgrading them to higher-grade DCIS, following examination of the surgically excised specimen.

METHODS

We studied all women with DCIS at preoperative biopsy in a large specialist cancer centre during 2000-2014. Information from clinical records, mammography, and pathology specimens from both preoperative biopsy and excised specimen were abstracted. Women suspected of having IBC during biopsy were excluded.

RESULTS

Among 606 preoperative biopsies showing DCIS, 15.0% (95% confidence interval 12.3-18.1) were upstaged to IBC and a further 14.6% (11.3-18.4) upgraded to higher-grade DCIS. The risk of upstaging increased with presence of a palpable lump (21.1% vs 13.0%, pdifference = 0.04), while the risk of upgrading increased with presence of necrosis on biopsy (33.0% vs 9.5%, pdifference < 0.001) and with use of 14G core-needle rather than 9G vacuum-assisted biopsy (22.8% vs 7.0%, pdifference < 0.001). Larger mammographic size increased the risk of both upgrading (pheterogeneity = 0.01) and upstaging (pheterogeneity = 0.004).

CONCLUSIONS

The risk of upstaging of DCIS in preoperative biopsies is lower than previously estimated and justifies conducting randomized clinical trials testing the safety of active surveillance for lower grade DCIS. Selection of women with low grade DCIS for such trials, or for active surveillance, may be improved by consideration of the additional factors identified in this study.

Feasibility of radioguided occult lesion localization of clip-marked lymph nodes for tailored axillary treatment in breast cancer patients treated with neoadjuvant systemic therapy

Background

Selective removal of initially tumor-positive axillary lymph nodes in breast cancer patients who underwent neoadjuvant systemic treatment (NST) improves the accuracy of nodal staging and provides the opportunity for more tailored axillary treatment. This study evaluated whether radioguided occult lesion localization (ROLL) of clip-marked lymph nodes is feasible in clinical practice.

Methods

Prior to NST, a clip marker was placed inside a proven tumor-positive lymph node in all breast cancer patients (cTis-4N1-3 M0). After NST, technetium-99m-labeled macroaggregated albumin was injected in the clip-marked lymph nodes. The next day, these ROLL-marked nodes were selectively removed at surgery to evaluate the pathological response of the axilla.

Results

Thirty-seven patients (38 axillae) underwent clip insertion. After NST, the clip was visible by ultrasound in 36 procedures (95%). In the other two patients, the ROLL-node injection was performed in a sonographically suspicious unclipped node (1), and near the clip under computed tomography guidance (1). Initial surgery successfully identified the ROLL-marked node with clip in 33 procedures (87%). Removed specimens in the other five procedures contained only the sonographically suspicious tumor-positive unclipped node (1), a node with signs of complete response but no clip (2), a clip without node (1), and tissue without node nor clip, and a second successful ROLL-node procedure was performed (1). Overall, 10 ROLL-marked nodes had no residual disease.

Conclusions

This study demonstrates that the ROLL procedure to identify clip-marked lymph nodes is feasible. This facilitates selective removal at surgery and may tailor axillary treatment in patients treated with NST.

Towards the use of diffuse reflectance spectroscopy for real-time in vivo detection of breast cancer during surgery

Background

Breast cancer surgeons struggle with differentiating healthy tissue from cancer at the resection margin during surgery. We report on the feasibility of using diffuse reflectance spectroscopy (DRS) for real-time in vivo tissue characterization.

Methods

Evaluating feasibility of the technology requires a setting in which measurements, imaging and pathology have the best possible correlation. For this purpose an optical biopsy needle was used that had integrated optical fibers at the tip of the needle. This approach enabled the best possible correlation between optical measurement volume and tissue histology. With this optical biopsy needle we acquired real-time DRS data of normal tissue and tumor tissue in 27 patients that underwent an ultrasound guided breast biopsy procedure. Five additional patients were measured in continuous mode in which we obtained DRS measurements along the entire biopsy needle trajectory. We developed and compared three different support vector machine based classification models to classify the DRS measurements.

Results

With DRS malignant tissue could be discriminated from healthy tissue. The classification model that was based on eight selected wavelengths had the highest accuracy and Matthews Correlation Coefficient (MCC) of 0.93 and 0.87, respectively. In three patients that were measured in continuous mode and had malignant tissue in their biopsy specimen, a clear transition was seen in the classified DRS measurements going from healthy tissue to tumor tissue. This transition was not seen in the other two continuously measured patients that had benign tissue in their biopsy specimen.

Conclusions

It was concluded that DRS is feasible for integration in a surgical tool that could assist the breast surgeon in detecting positive resection margins during breast surgery.

Trail registration NIH US National Library of Medicine–clinicaltrails.gov, NCT01730365. Registered: 10/04/2012 https://clinicaltrials.gov/ct2/show/study/NCT01730365

Abstract P2-03-10: Risk factors for upgrading and upstaging of pre-operative biopsies in ductal carcinoma in situ

Background: Ductal carcinoma in situ (DCIS), accounts for one fifth of all screen-detected neoplastic breast lesions. Contemporary research in DCIS focuses on separating lesions that need active treatment from those that can be safely left under surveillance. This, in turn, relies on accurate determination of invasive status and DCIS grade at time of initial biopsy. Most previous studies have examined factors associated with upstaging the diagnosis from DCIS to invasive breast cancer (IBC) following surgery, and few have evaluated factors associated with upgrading the diagnosis to a higher grade of DCIS. This is because upgrading has not traditionally influenced clinical management in the way that upstaging has done. However, recent interest in non-operative treatment for low-risk DCIS has meant that accurate determination of grade at time of initial biopsy has become more important. We aimed to compare risk factors for upgrading and upstaging of biopsies in DCIS.

Method: We undertook a cohort study of all women diagnosed with DCIS at a large specialist cancer centre between 2000–2014. Information from the clinical records was abstracted, including the pre-operative mammography (MMG) and pathology information from the initial biopsy. We also abstracted pathology information regarding the excised specimen in order to identify women whose diagnosis was subsequently upgraded or upstaged. We looked for factors that were predictive for upgrading or upstaging.

Result: A total of 641 women were diagnosed with DCIS at initial biopsy. Of these, 72 (11%) were upgraded: 26 (4%) from grade 1 to grade 2, 2 (0.3%) from grade 1 to grade 3 and 44 (7%) from grade 2 to grade 3. A further 115 (18%) were upstaged to IBC: 20 of these (3%) had grade 1 DCIS on initial biopsy, 47 (7%) had grade 2, 43 (7%) grade 3, and for 5 (1%) biopsy grade was not available. Necrosis on biopsy increased the risk of upgrading (with necrosis: 14% upgraded, without: 10% upgraded, p for difference 0.02) and also of upstaging (with necrosis: 23% upstaged, without: 15% upstaged, p for difference &lt;0.01). Lesions measuring ≥50 mm on MMG were more likely to be upgraded than smaller lesions (0-19 mm: 9% upgraded, 20-50 mm: 9% upgraded, ≥50 mm: 19% upgraded, p for heterogeneity &lt;0.01), while lesions measuring 20-50 mm and ≥50 mm were both more likely to be upstaged than lesions measuring 0-19 mm (0-19 mm: 9% upstaged, 20-50 mm: 23% upstaged and ≥50 mm: 21% upstaged, p for heterogeneity &lt;0.01). Fewer 9G vacuum-assisted biopsies than 14G core biopsies were upgraded (9G vacuum-assisted: 7% upgraded, 14G core: 15% upgraded, p for difference 0.01), while the effect of biopsy method on upstaging was not significant (9G vacuum-assisted: 12% upstaged, 14G core: 16% upstaged, p for difference 0.15). Presence of a palpable lump was not significantly associated with upgrading (palpable lump: 13% upgraded, no palpable lump: 10% upgraded, p for difference 0.19) but increased the risk of upstaging (palpable lump: 23% upstaged, no palpable lump: 16% upstaged, p for difference 0.02).

Conclusion: Our findings suggest that consideration of MMG lesion size and necrosis on biopsy may be helpful in selecting low-risk women for non-operative management of DCIS, as may use of the 9G vacuum-assisted method of biopsy.

Citation Format: Mannu GS, Groen E, Wang Z, Schaapveld M, Lips E, Chung M, Joore I, Leeuwen Fv, Teerstra J, Winter-Warnars GAO, Darby SC, Wesseling J. Risk factors for upgrading and upstaging of pre-operative biopsies in ductal carcinoma in situ [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-03-10.

Abstract P3-01-07: BI-RADS classification in daily practice: Keep it simple

This abstract was withdrawn by the authors.

Should we screen BRCA1 mutation carriers only with MRI? A multicenter study

BRCA1 mutation carriers are offered screening with MRI and mammography. Aim of the study was to investigate the additional value of digital mammography over MRI screening. BRCA1 mutation carriers, who developed breast cancer since the introduction of digital mammography between January 2003 and March 2013, were included. The images and reports were reviewed in order to assess whether the breast cancers were screen-detected or interval cancers and whether they were visible on mammography and MRI, using the breast imaging and data system classification allocated at the time of diagnosis. In 93 BRCA1 mutation carriers who underwent screening with MRI and mammography, 82 invasive breast cancers and 12 ductal carcinomas in situ (DCIS) were found. Screening sensitivity was 95.7 % (90/94). MRI detected 88 of 94 breast cancers (sensitivity 93.6 %), and mammography detected 48 breast cancers (sensitivity 51.1 %) (two-sided p < 0.001). Forty-two malignancies were detected only by MRI (42/94 = 44.7 %). Two DCIS were detected only with mammography (2/94 = 2.1 %) concerning a grade 3 in a 50-year-old patient and a grade 2 in a 67-year-old patient. Four interval cancers occurred (4/94 = 4.3 %), all grade 3 triple negative invasive ductal carcinomas. In conclusion, digital mammography added only 2 % to the breast cancer detection in BRCA1 patients. There was no benefit of additional mammography in women below age 40. Given the potential risk of radiation-induced breast cancer in young mutation carriers, we propose to screen BRCA1 mutation carriers yearly with MRI from age 25 onwards and to start with mammographic screening not earlier than age 40.