Outcomes and clinicopathologic characteristics associated with disseminated tumor cells in bone marrow after neoadjuvant chemotherapy in high-risk early stage breast cancer: the I-SPY SURMOUNT study

PURPOSE

Disseminated tumor cells (DTCs) expressing epithelial markers in the bone marrow are associated with recurrence and death, but little is known about risk factors predicting their occurrence. We detected EPCAM+/CD45- cells in bone marrow from early stage breast cancer patients after neoadjuvant chemotherapy (NAC) in the I-SPY 2 Trial and examined clinicopathologic factors and outcomes.

METHODS

Patients who signed consent for SURMOUNT, a sub-study of the I-SPY 2 Trial (NCT01042379), had bone marrow collected after NAC at the time of surgery. EPCAM+CD45- cells in 4 mLs of bone marrow aspirate were enumerated using immunomagnetic enrichment/flow cytometry (IE/FC). Patients with > 4.16 EPCAM+CD45- cells per mL of bone marrow were classified as DTC-positive. Tumor response was assessed using the residual cancer burden (RCB), a standardized approach to quantitate the extent of residual invasive cancer present in the breast and the axillary lymph nodes after NAC. Association of DTC-positivity with clinicopathologic variables and survival was examined.

RESULTS

A total of 73 patients were enrolled, 51 of whom had successful EPCAM+CD45- cell enumeration. Twenty-four of 51 (47.1%) were DTC-positive. The DTC-positivity rate was similar across receptor subtypes, but DTC-positive patients were significantly younger (p = 0.0239) and had larger pretreatment tumors compared to DTC-negative patients (p = 0.0319). Twenty of 51 (39.2%) achieved a pathologic complete response (pCR). While DTC-positivity was not associated with achieving pCR, it was significantly associated with higher RCB class (RCB-II/III, 62.5% vs. RCB-0/I; 33.3%; Chi-squared p = 0.0373). No significant correlation was observed between DTC-positivity and distant recurrence-free survival (p = 0.38, median follow-up = 3.2 years).

CONCLUSION

DTC-positivity at surgery after NAC was higher in younger patients, those with larger tumors, and those with residual disease at surgery.

Abstract PS2-07: Outcomes associated with disseminated tumor cells at surgery after neoadjuvant chemotherapy in high-risk early stage breast cancer: The I-SPY SURMOUNT study

Background: Disseminated tumor cells (DTCs) in bone marrow detected after treatment may represent occult residual disease. We enumerated DTCs after neoadjuvant chemotherapy (NACT) in patients (pts) diagnosed with high-risk early stage breast cancer and examined the relationship of these cells with response and survival. Methods: I-SPY SURMOUNT is a sub-study of the I-SPY 2 TRIAL (NCT01042379). Pts enrolled on I-SPY 2, who signed consent for this sub-study, had bone marrow aspirates (BMA) collected after NACT at the time of surgery. DTCs were isolated and enumerated from BMA using immunomagnetic enrichment/flow cytometry (IE/FC). DTCs were defined as EPCAM-positive and CD45-negative nucleated cells. Samples were considered positive using a predetermined threshold of >4 DTCs per mL (Magbanua et al, unpublished data). Pathologic response was assessed using the residual cancer burden (RCB) method at local sites, and pts underwent standard adjuvant therapy if indicated and follow up for recurrence events and death. Relationship of DTCs with clinicopathologic variables was examined using Chi-squared test. Group means were compared using t tests. The log-rank test was used to compare survival curves. Results: A total of 73 patients were enrolled, 51 of whom had successful DTC assessment. The median DTC per mL was 4 (interquartile range 1.2-11.6). 24/51 (47%) were DTC-positive. Clinical characteristics by DTC status are shown in the table. DTC-positive pts were significantly younger (p=0.02) and had larger pretreatment tumors (longest diameter by magnetic resonance imaging) compared to DTC-negative pts (p=0.032). DTCs were not associated with receptor subtype. Thirty pts (41%) achieved a pathologic complete response (pCR). DTCs were not associated with pCR (p= 0.166); however, DTC-positive patients were significantly more likely to have residual cancer (RCB-II/III) after NACT compared to DTC-negative patients (OR 3.3, p=0.037). Median follow up of this cohort was 2.8 years (range: 0.9-4.8). Interim survival analysis showed that DTCs were not significantly correlated with EFS (p=0.6) or DRFS (p=0.41). Conclusions: Detection of DTCs at surgery after NACT is significantly more common in young patients, those with larger tumors, and those with residual disease at surgery. While these associations suggest higher risk for later recurrence, larger studies and longer follow up are necessary to determine if DTCs add prognostic value over pathologic evaluation alone for pts receiving NACT.

Citation Format: Mark Jesus M Magbanua, Laura van 't Veer, Amy Clark, A. Jo Chien, Judy Boughey, Heather Han, Anne Wallace, Heather Beckwith, Minetta Liu, Christina Yau, E. Paul Wileyto, Lamorna Brown Swigart, Jane Perlmutter, Lauren Bayne, Shannon Deluca, Stephanie Yee, Erica Carpenter, Laura Esserman, John Park, Lewis Chodosh, Angela DeMichele. Outcomes associated with disseminated tumor cells at surgery after neoadjuvant chemotherapy in high-risk early stage breast cancer: The I-SPY SURMOUNT study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-07.

Abstract PD9-11: Identifying breast cancer survivors with dormant disseminated tumor cells: The PENN-SURMOUNT screening study

Background: Patients (pts) treated for early stage breast cancer have a 30% lifetime risk of developing incurable, distant metastatic disease. Current models suggest that this occurs through escape of cells from the primary tumor into the circulation and subsequent sequestration of “disseminated tumor cells” (DTCs), in the bone marrow and other sequestration sites, where they enter dormancy. DTCs identified by immunohistochemistry (IHC) are associated with poor prognosis in longitudinal studies and meta-analyses, increasing odds of recurrence by approximately 2 to 5-fold. However, little is known about the test characteristics of the DTC-IHC assay, clinical DTC detection rates over time, and patient and disease risk factors that can identify pts harboring these cells.

Methods: The PENN-SURMOUNT Screening Study (NCT 02732171) is a prospective, longitudinal study examining bone marrow and blood biomarkers of recurrence among pts within 5 years of diagnosis who have completed therapy for primary breast cancer (with the exception of endocrine therapy). Pts with positive lymph nodes, triple negative receptors, ER-positivity with RS ≥ 25 and/or high-risk MammaPrint (MP), or residual disease after neoadjuvant chemotherapy were screened with bone marrow aspirate (BMA) for presence of DTCs. A positive DTC-IHC result is defined by the presence of at least one pancytokeratin-DAB positive cell utilizing the methods of Naume et al. Cytospin slides prepared from the BMA are independently reviewed by two pathologists with adjudication for the presence of DTCs; Pts who screen negative for DTCs are offered repeat screening annually. Pts who screen positive are referred to an interventional clinical trial (CLEVER, NCT 03032406).

Results: A total of 194 pts screened eligible for enrollment on PENN-SURMOUNT between 6/2016 and 3/2020. Of these, 158 consented and 151 underwent BMA with successful IHC analysis on 100%. Pts came from 22 U.S. states; ≥ 1/3 traveled over 50 miles to the study center. At baseline BMA, 36/151 (24%) had at least 1 measurable DTC by IHC. Patient characteristics and DTC distribution among subpopulations are shown in Table 1. Of the 78/115 who were initially DTC negative and continued to be eligible for repeat screening, as of 3/2020, 46 (59%) returned for at least one repeat BMA. 13/46 (28%) had at least 1 detectable DTC on 1 of up to 3 subsequent follow up assessments for a total DTC positivity rate of 32.5% (49/151). 48 (98%) DTC+ pts have subsequently enrolled on the CLEVER trial.

Conclusions: BMA assessment for DTCs is feasible in pts with high risk, early stage breast cancer. DTCs are detected in up to a third of breast cancer survivors with repeat assessment during the surveilance period. DTC positivity rates are relatively similar across all receptor subtypes, and after both neoadjuvant and adjuvant chemotherapy. Pts harboring DTCs are highly likely to enroll on interventional trials designed to reduce recurrence risk.

Table 1. Patient characteristics and distribution of % DTC positivity among subpopulationsDTC+ (N=49)DTC- (N=102)Total (N=151)DTC+ Rate (Overall: 32.5%)DEMOGRAPHICSMedian Age at BMA (yrs)51.9 (43.9-60.6*)50.5 (42.9-58.1)50.5 (43.8-58.8)N/ARaceCaucasian44 (89.8%)91 (89.2%)135 (89.4%)32.6%African American5 (10.2%)9 (8.8%)14 (9.3%)35.7%Other0 (0%)2 (2.0%)2 (1.3%)0%Menopausal StatusPre-15 (30.6%)34 (33.3%)49 (32.5%)30.6%Post-34 (69.4%)68 (66.7%)102 (67.5%)33.3%BMI at BMA (kg/m2)24.2 (21.9-28.9*)26.9 (23.4-31.4)26.1 (22.8-30.4)N/ARECEPTOR STATUSER/PR+ HER2neg (by ASCO/CAP)24 (49.0%)51 (50.0%)75 (49.7%)32.0%HER2+ (any ER/PR)9 (18.4%)12 (11.8%)21 (13.9%)42.9%ER/PRneg HER2neg23 (46.9%)48 (47.1%)71 (47.0%)32.4%RISK CRITERIALymph Node Positive24 (49.0%)65 (63.7%)89 (58.9%)27.0%Triple Negative (ER/PR<10%)27 (55.1%)50 (49.0%)77 (51.0%)35.0%Non-pCR11 (22.4%)25 (24.5%)36 (23.8%)30.6%RS ≥ 25 and/or High Risk MP6 (12.2%)8 (7.8%)14 (9.3%)42.9%Median T size (cm) -excluding NACT2.1 (1.5-2.9*)1.8 (1.3-2.8)1.8 (1.3-2.9)N/APRIOR THERAPYAdjuvant Chemo25 (51.0%)60 (58.8%)85 (56.3%)29.4%Neoadjuvant Chemo22 (44.9%)41 (40.2%)63 (41.7%)34.9%Endocrine Therapy19 (38.8%)47 (46.1%)66 (43.7%)28.8%XRT29 (59.2%)75 (73.5%)104 (69.3%^)27.9%*Ranges represent interquartile range^ XRT data not available on 1 patient; n=150 was used to figure percentage

Citation Format: Lauren Bayne, Isoris Nivar, Brooke Goodspeed, Shannon Deluca, E. Paul Wileyto, Natalie Shih, Anupma Nayak, Michael D Feldman, Joshua Edwards, Kevin Fox, Jennifer M. Matro, Susan Domchek, Hayley Knollman, Rachel Jankowitz, Angela Bradbury, Payal D. Shah, Jewell Graves, George Woodfield, Elizabeth Chislock, Jianping Wang, George Belka, Lewis A. Chodosh, Amy S. Clark, Angela DeMichele. Identifying breast cancer survivors with dormant disseminated tumor cells: The PENN-SURMOUNT screening study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD9-11.

Changes in alkaline phosphatase isoenzyme activity in tissues and plasma of Atlantic salmon (Salmo salar) before and during smoltification and gonadal maturation

Changes in tissue and plasma isoenzymes of alkaline phosphatase (ALP) were qualitatively and quantitatively determined for male and female Atlantic salmon parr, silvery parr, smolt, immature grilse, prespawning grilse and postspawning grilse using cellulose acetate electrophoresis, densitometry and spectrophotometry. Tissue ALP isoenzymes were isolated from intestine, kidney, bone, liver, and gonad and compared to plasma isoenzymes. Parr plasma displayed three isoenzymes from bone and liver (slow and fast). During smoltification, ALP activity increased in tissue extracts from liver, gonad, and kidney of males and females. Total plasma ALP activity also increased and was due to slow and fast liver isoenzymes. During ovarian development, total ALP plasma activity increased in females and was due mostly to liver isoenzymes and an incompletely identified isoenzyme or isoenzyme mixture (band 2). However, in males total ALP plasma activity did not increase during maturation and no band 2 was evident. In male and female maturing adult grilse, bone ALP activity declined and the isoenzyme band evident in parr plasma could not be detected. ALP activity declined in the plasma of postspawning males and females. In females this was due partly to the total clearance of band 2 from the plasma, together with lowered levels of liver isoenzymes. Treatment of postspawned grilse in February and March with triiodothyronine and thyroxine elevated plasma thyroid hormone levels and increased plasma ALP levels. In conclusion, plasma ALP isoenzyme activities change with physiological state, and knowledge of the conditions governing these changes is important when using these enzymes as a diagnostic tool.

Serial overnight recordings of intracarpal canal pressure in carpal tunnel syndrome patients with and without wrist splinting

In 15 carpal tunnel syndrome patients pressure was measured during the day and at 2-hourly intervals from midnight to 6 a.m., via a catheter introduced into the carpal canal, using the constant infusion technique. Intracarpal tunnel pressure of the patients always exceeded the critical pressure of 30 mmHg and the highest values were found at 6 a.m. Slightly lower pressures were found when the wrist was splinted, but the difference was not significant, nor were critical pressure levels prevented by splinting.

Carpal tunnel syndrome: correlations between pressure measurement and intraoperative electrophysiological nerve study

In 19 carpal tunnel syndrome (CTS) patients and 4 control subjects a catheter was introduced into the carpal tunnel and slowly retracted in 5 mm steps. Pressure was measured with the continuous infusion technique. In the same group of patients and controls, median nerve antidromic sensory action potential (aSAP) was detected intraoperatively stimulating proximally (S1), in the center (S2), and distally (S3) to the carpal tunnel and recording from the third finger (R). Sensory conduction velocity (SCV) and aSAP amplitude were considered in S1-S2, S2-S3 and S3-R segments. The intracarpal tunnel pressure was significantly higher in CTS patients than in controls, with the highest values located between 25 and 35 mm distal to the proximal border of the flexor retinaculum. SCV and aSAP amplitude were also decreased most often in the distal part (S2-S3) of the carpal tunnel.

Vascularized nerve graft: a clinical contribution

The authors present 4 cases of vascularized nerve graft. The results were better than those obtained with traditional grafting. The indication is a rare one, and the experimental results are contradictory. Indications are limited to Volkmann ischemic syndromes, post-actinic lesions of the brachial plexus, infections and finally, post-burning scarring. Nevertheless, traditional nerve grafts remain the treatment of choice for peripheral nerve lesions which cannot undergo direct suturing.

Carpal-tunnel pressure

Using the constant infusion technique, we have measured the pressures within the carpal tunnel in 30 hands in patients with carpal tunnel syndrome and in 4 hands in control subjects. The mean pressure in the normal, control subjects was 13 mmHg and in the carpal tunnel syndrome patients 26 mmHg. In the normal subjects the pressures did not change along the canal, whereas in the patients the values in the middle section were 50 percent higher than the mean. Our results correspond to reports of computed tomography and magnetic resonance recordings of nonuniform dimension of the carpal tunnel.