Abstract OT2-05-02: International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1)

Breast cancer (BC) is so-called “systemic disease”, because disseminated cancer cells in bone marrow and blood are detected even in early BC patients. Despite adjuvant therapy and postoperative radiation therapy, patients with triple negative BC and Luminal B-like BC often relapse early and systemic therapy is the only way to control disease progression. On the other hand, some BC patients relapse several years later. In such patients, oligometastases are occasionally diagnosed, because metastatic cancer cells are slowly growing and indolent. Oligometastatic BC is defined as low volume metastatic disease with limited number and size of metastatic lesions (up to five and not necessarily in the same organ). This definition is proposed in the Advanced Breast Cancer guidelines that are developed as a joint effort from European School of Oncology and European Society of Medical Oncology. Several retrospective studies demonstrated survival benefit of locoregional therapy in addition to systemic therapy. Locoregional therapy consisted of surgical resection, radiation therapy, ablation therapy, etc. However, it remains unclear about survival benefit of combined therapy in oligometastatic BC. To improve the standard of cancer treatment through the cooperate studies on more effective therapeutic strategies based on drugs, surgery and/or radiotherapy, Federation of Asian Clinical Oncology (FACO) was established in 2012 by Chinese Society of Clinical Oncology (CSCO), Korean Society of Medical Oncology (KSMO) and Japan Society of Clinical Oncology (JSCO). Thus, FACO conducted a retrospective cohort study on oligometastatic BC. The primary endpoint is to compare the estimated 5-year overall survival (OS) of oligometastatic BC patients treated with combined therapy and systemic therapy alone. To hypothesize that combined therapy has more advantage of OS in oligometastatic BC, the 5-year OS rates are expected to be 50% and 40%, respectively. The estimated sample size is calculated to be the number of 698 cases (349 cases in each group) needed to prove the superiority of survival with a two-sided type I error rate of 5% and a statistical power of 80%. Case registry opened in February 2018 and will close in January 2019. We planned to register 700 cases, i.e., 234 cases each from investigators of CSCO, KSMO and JSCO. Update information will be discussed.

Citation Format: Imoto S, Futamura M, Toi M, Fujiwara Y, Ueno T, Im Y-H, Im S-A, Ahn SG, Lee JE, Park YH, Wang K, Kitagawa Y, Nishiyama M. International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-05-02.

Abstract P4-08-29: Lymphatic invasion is an independent risk factor in patients with small node-negative luminal breast cancer

[Background]

In patients with node-negative (N0), hormone receptor-positive, human epidermal growth factor receptor (HER2) -negative (luminal) breast cancer, the impact of lymphatic invasion (ly) on the prognosis remains to be clarified.

[Methods]

Among 3,158 patients with primary breast cancers who underwent surgery in our institute from January 2007 to December 2009, we analyzed 1027 N0 luminal invasive breast cancers without preoperative systemic therapy. The luminal breast cancer was defined as hormone receptor-positive (ER of ≥ 10% or PgR of ≥ 10%) and HER2-negative (immunohistochemistry: 0, 1+ or FISH: ratio < 2.0) cancer in the postoperative pathological specimen. ly was defined as positive when cancer cell nests were detected within the lymph duct in the whole specimen. N0 was confirmed pathologically by the sentinel lymph node biopsy in all the patients. The Fisher's exact test was used for comparison between different categories. The distant recurrence rate (DRR) was analyzed using the Kaplan-Meier method and the log-rank test. For multivariate analysis, Cox's regression analysis was performed.

[Results]

The median follow-up period was 103.8 months (range: 5.6-128.8). Recurrence with distant metastasis occurred in 26 patients (2.5%). There were 5 (0.7%) deaths related to breast cancer. ly was detected in 240 patients (23.4%). In the ly-positive group, the tumor size was larger (p = 0.007), and the nuclear grade (NG) was higher (p < 0.001) than in the ly-negative group. Postoperative endocrine therapy (p < 0.001) and postoperative chemotherapy (p < 0.001) were more frequently employed for patients with ly-positive tumor. The univariate analysis showed that ly positivity (p < 0.001), large tumor size (p < 0.001), high NG (p < 0.001), PgR negativity (p = 0.002) and the history of adjuvant chemotherapy (p < 0.001) were associated with high DRR. In the multivariate analysis, large tumor size (p = 0.007) and PgR negativity (p = 0.015) remained significant. Although positive ly had a risk ratio of 2.2, it was not an independent risk factor.When restricted to T1 tumor (n = 899), the aforementioned factors still showed prognostic value in the univariate analysis, among which ly positivity (p = 0.004)remained significant together with PgR negativity (p = 0.047)in themultivariate analysis.The 8-year DRR was very favorable (0.8%) in patients with ly-negative T1N0 tumor while it was modest (6.6%) in patients with ly-positive T1N0 tumor (p < 0.001). Only 1.3% of the patients had received adjuvant chemotherapy in the ly-negative group while 27% of the patients had in the ly-positive group.

[Conclusion]

Lymphatic invasion was associated with higher DRR although it was not independent in the multivariate analysis among patients with N0 luminal breast cancer. When restricted to patients with T1N0 luminal breast cancer, the presence of ly was independently associated with higher risk of distant recurrence. It suggests that the assessment of ly is clinically more relevant when considering treatment options for small luminal breast cancer.

Citation Format: Abe T, Ito Y, Fukada I, Shibayama T, Ono M, Kobayashi T, Kobayashi K, Takahashi S, Horii R, Akiyama F, Iwase T, Ueno T, Ohno S. Lymphatic invasion is an independent risk factor in patients with small node-negative luminal breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-29.

Abstract P5-18-11: Prognostic impact and possible pathogenesis of lymph node metastasis in ductal carcinoma in situof the breast

Background: By definition, ductal carcinoma in situ (DCIS) does not metastasize to the lymph nodes. However, since the introduction of molecular whole-node analysis using the one-step nucleic acid amplification (OSNA) assay for sentinel node (SN) biopsies, the number of DCIS patients with SN metastasis has increased. The clinical management of node-positive DCIS remains controversial because these patients can be treated as different stages based on the pathogenesis: e.g. occult invasive cancer with true nodal metastasis (T1N1) or true DCIS with iatrogenic dissemination of benign or tumor cells into lymph node (TisN0). In this retrospective cohort study, we aimed to elucidate the pathogenesis of nodal metastasis in DCIS and the clinical management of node-positive DCIS.

Patients and Methods: Subjects comprised of 427 patients with a routine postoperative diagnosis of DCIS who underwent SN biopsy using the OSNA assay between 2009 and 2012. The cut-off values of the OSNA assay for negative/positive results and micro/macrometastasis were defined at 250 and 5,000 copies/μL of cytokeratin 19 mRNA, respectively. In the SN-positive patients, all paraffin blocks containing the primary tumor were step-sectioned with 0.5-mm intervals until the tissue was exhausted, and all microscopic slides were examined for detecting occult invasions. Afterwards, the patients were classified into three cohorts based on the SN status and occult invasion: (1) no SN metastasis (TisN0), (2) SN metastasis without occult invasion (TisN1), and (3) SN metastasis with occult invasion (T1N1). Tumor characteristics including risk factors of occult invasions (e.g. large size, comedo-type), prognosis, and SN and non-SN status were compared among the three cohorts. The median follow-up time was 73.6 months.

Results: Of the 427 patients, 408 (95.6%) were SN-negative and 19 (4.4%) were SN-positive. By examining a total of 1,421 step-sectioned slides, 9 of the 19 SN-positive patients had occult invasions in the primary tumors. Overall, 408 (95.6%), 10 (2.3%), and 9 (2.1%) were classified into the TisN0, TisN1, and T1N1 cohorts, respectively. Either of adjuvant endocrine therapy or chemotherapy was given much more in the TisN1 and T1N1 cohorts than in the TisN0 cohort (80.0% and 88.9% vs. 5.4%).Other tumor characteristics were similar among the three cohorts. Although one patients had distant recurrence in the TisN0 cohort, none had locoregional or distant recurrences in the TisN1 and T1N1 cohorts. Regarding the lymph node status in the TisN1 and T1N1 cohorts, median tumor burdens in the SN are 590 and 310 copies/μL, and 2 (20.0%) and 2 (22.2%) patients had additional non-SN metastasis in the axillary dissection materials, respectively.

Conclusions: Tumor characteristics and prognosis were similar among the three cohorts albeit the TisN1 and T1N1 cohorts tended to received adjuvant systemic therapy. Moreover, the SN and non-SN status were similar between the TisN1 and T1N1 cohorts. Therefore, pathogenesis of nodal metastasis in DCIS cannot uniformly be explained, and tumors with different stages may be mixed in the node-positive DCIS. Thus, considering the favorable prognosis of node-positive DCIS, the clinical management should be determined on a case-by-case basis.

Citation Format: Yonekura R, Osako T, Iwase T, Ogiya A, Ueno T, Ohno S, Akiyama F. Prognostic impact and possible pathogenesis of lymph node metastasis in ductal carcinoma in situof the breast [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-11.

Abstract P3-03-23: Which factor of metastatic lymph nodes–The number, tumor volume or anatomical location–Is independently prognostic in breast cancer? - A prospective cohort study using molecular whole-node analysis of all removed axillary nodes

Background: Axillary lymph node status is one of the most powerful prognostic factors in breast cancer. However, it remains unknown which factor of metastatic lymph nodes–the number, tumor volume or anatomical location–is independently prognostic. Conventional pathological examinations of lymph nodes have limited ability to accurately measure metastatic tumor volume due to the partial evaluation of nodes. On the other hand, the one-step nucleic acid amplification (OSNA) assay, a novel molecular method, can quantify the tumor volume in a whole node based on cytokeratin 19 (CK19) mRNA copy number. In this prospective cohort studyusing the OSNA whole-node analysis, we aimed to elucidate the independent prognostic factor of lymph node metastasis in breast cancer.

Patients and Methods: The subjects consisted of 307 cN0 patients with invasive breast cancer, who underwent axillary dissection after a metastatic sentinel node (SN) biopsy and whose SNs and non-SNs were all examined using the OSNA whole-node assaybetween 2009 and 2012.The cut-off values of the OSNA assay for negative/positive results and micro/macrometastasis were defined at 250 and 5,000 copies/μL of CK19 mRNA, respectively. The total tumor volume in the SN or non-SN was defined as the sum of CK19 mRNA copy numbers from all samples in the SN or non-SN. The cut-off value for the total tumor volume in the SN was set at 2,810 copies/μL according to our previous study (Osako et al. Br J Cancer 2017). The anatomical location of metastasis was classified into Level I (confined to SN), Level I (spread to non-SN), or Level II/III. Predictive factors for distant disease-free survival (DDFS) were investigated using the univariate log-rank tests and multivariate Cox proportional hazards models.The median follow-up time was 6.1 years (range, 0.2–8.6).

Results: Of the 307 patients, 130 (42.3%) and 177 (57.7%) had the total tumor volume <2,810 and ≥2,810 copies/μL in the SN, respectively. Five-year DDFS was 96.0% in the entire cohort. In the univariate analysis, DDFS was significantly related to the pT classification, grade, hormone receptor status, triple-negative subtype, total tumor volume in the SN and cytotoxic chemotherapy. However, DDFS was not significantly related to the number of metastatic or macrometastatic nodes in the SN, non-SN, or all nodes (i.e. SN + non-SN); the total tumor volume in the non-SN or all nodes; the AJCC pN classification; or the anatomical location of metastasis. In the multivariate analysis, the total tumor volume in the SN (<2810 vs. ≥2810 copies/μL, hazard ratio 5.2, 95% confidence interval 1.2–23.2, P=0.03) and cytotoxic chemotherapy (- vs. +, hazard ratio 0.05, 95% confidence interval 0.02–0.17, P<0.001) remained significant.

Conclusions: The total tumor volume in the SN was the independent prognostic factor of lymph node metastasis in SN-positive invasive breast cancer. Accurate evaluation of metastatic tumor burden in the SN can be important for predicting prognosis and may help to guide the precise therapeutic decision making for breast cancer patients.

Citation Format: Osako T, Iwase T, Ushijima M, Ogiya A, Ueno T, Ohno S, Akiyama F. Which factor of metastatic lymph nodes–The number, tumor volume or anatomical location–Is independently prognostic in breast cancer? - A prospective cohort study using molecular whole-node analysis of all removed axillary nodes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-23.

Morphometric geometrical analysis to determine the centre of the acetabular component placement in Crowe type IV hips undergoing total hip arthroplasty

AIMS

We analyzed the acetabular morphology of Crowe type IV hips using CT data to identify a landmark for the ideal placement of the centre of the acetabular component, as assessed by morphometric geometrical analysis, and its reliability.

PATIENTS AND METHODS

A total of 52 Crowe IV hips (42 patients; seven male, 35 female; mean age 68.5 years (32 to 82)) and 50 normal hips (50 patients; eight male, 42 female; mean age 60.7 years (34 to 86)) undergoing total hip arthroplasty were retrospectively identified. In this CT-based simulation study, the acetabular component was positioned at the true acetabulum with a radiological inclination of 40° and anteversion of 20°. Acetabular shape and the position of the centre of the acetabular component were analyzed by morphometric geometrical analysis using the generalized Procrustes analysis.

RESULTS

The acetabular shapes of Crowe IV hips were distinctively triangular; the ideal position of the centre of the acetabular component was superior on the posterior bony wall. The first and second relative warps explained 34.2% and 18.4% of the variance, respectively, compared with that of 28.6% and 18.0% in normal hips. We defined the landmark as one-third the distance from top on the posterior bony wall in Crowe IV hips. The average distance from the centre of the acetabular component was 5.6 mm.

CONCLUSION

Crowe IV hips are distinctively triangular; the point one-third from the top on the posterior bony wall was a useful landmark for placing the acetabular component.

Exposure-Response Analysis for Efficacy of Daclatasvir, Asunaprevir, and Beclabuvir Combinations in HCV-Infected Patients

The combination regimen of daclatasvir, asunaprevir, and beclabuvir (3DAA regimen) was developed as a fixed-dose combination for the treatment of hepatitis C virus (HCV) infection in Japan. The objectives of this analysis were to characterize the relationship between drug exposure and sustained virologic response at posttreatment week 12 (SVR12) in HCV-infected subjects and to evaluate the impact of demographic covariates and clinical factors on the exposure-response (E-R) relationship. The E-R efficacy analysis was performed with data from phase 2 and phase 3 studies in HCV-infected subjects treated with the 3DAA regimen. The relationship between the probability of achieving SVR12 and exposure to daclatasvir, asunaprevir, and beclabuvir was described using a logistic regression model and included assessments of the potential covariate effects. The impacts of the covariates on the rate of SVR12 and interactions of covariates with the individual drug effects were tested. The final model for SVR12 included effects of non-genotype-1a status, resistance-associated NS5A-Q30 substitution in genotype-1a subjects, and baseline RNA level on the intercept, and effect of prior peg-interferon failure on the beclabuvir slope. Sex, race, age, weight, fibrosis score, alanine transaminase, and cirrhosis status had no statistically significant impact on the rate of SVR12. The individual E-R relationships with each drug, were relatively flat, and the effects of exposure were not significant. With the exception of the NS5A-Q30 substitution in genotype-1a subjects, statistically significant covariate effects had little impact on SVR12 rates. Overall, the E-R model was developed that captured the high SVR12 rates and the effect of covariates for the 3DAA regimen in HCV-infected patients.

Impact of Donor Age on Outcome of Intestinal Transplantation in Japan

BACKGROUND

Donor age for intestinal transplantation (ITx) is somewhat younger than that for other solid organs. Clear criteria for adequate donors have not been established. There is a donor scarcity for ITx in Japan due to the shortage of young donors.

METHODS

We reviewed outcomes associated with ITx in Japan based on donor age for cadaveric and living donation.

RESULTS

Standardized report forms were sent to all known ITx programs, asking for information on ITxs performed between 1996 and 2016. All programs responded. Patient and graft survival estimates were obtained using the Kaplan-Meier method. Five institutions provided data on 27 grafts in 24 patients. There were 14 cadaveric and 13 living donor transplants. Median donor age for ITxs was 40 (range, 17-60) years. Graft survival at 5 years was 66% for patients >40 years old (n = 18) and 47% for those <40 years old (n = 9), not a statistically significant difference (P = .49). Graft survival at 5 years was 60% in those >50 years old (n = 5) and 57% for those <50 years old (n = 22), again not a significant difference (P = .27).

CONCLUSION

There is no difference in survival between for those with donor age <40 vs >40 years. Donor age for ITx can be extended from >40 to up to 50 years, which may help to mitigate the donor shortage. It will be necessary to clarify the donor criteria for ITx through accumulation of further data on ITx.

Pulmonary Arterial Pressure Management Based on Oral Medicine for Pediatric Living Donor Liver Transplant With Portopulmonary Hypertension

Pediatric living donor liver transplantation (LDLT) in patients with advanced portopulmonary hypertension (PoPH) is associated with poor prognoses. Recently, novel oral medications, including endothelin receptor antagonists (ERAs), phosphodiesterase 5 (PDE5) inhibitors, and oral prostacyclin (PGI2) have been used to treat PoPH. Pediatric patients with PoPH who underwent LDLT from 2006 to 2016 were enrolled. Oral pulmonary hypertension (PH) medication was administered to control pulmonary arterial pressure (PAP). Four patients had PoPH. Their ages ranged from 6 to 16 years, and their original diseases were biliary atresia (n = 2), portal vein obstruction (n = 1), and intrahepatic portal systemic shunt (n = 1). For preoperative management, 2 patients received continuous intravenous PGI2 and 2 oral medications (an ERA alone or an ERA and a PDE5 inhibitor), and 2 received only oral drugs (an ERA and a PDE5 inhibitor). One patient managed only with intravenous PGI2 died. In the remaining 3 cases, intravenous PGI2 or NO was discontinued before the end of the first postoperative week. Postoperative medications were oral PGI2 alone (n = 1), an ERA alone (n = 1), or the combination of an ERA and a PDE5 inhibitor (n = 1). An ERA was the first-line therapy, and a PDE5 inhibitor was added if there was no effect. New oral PH medications were effective and safe for use in pediatric patients following LDLT. In particular, these new oral drugs prevent the need for central catheter access to infuse PGI2.

Early Outcomes of Living-Donor Kidney Transplantation With Immunosuppression Therapy Induction With Tacrolimus Extended-Release: A Comparison With Cyclosporine

BACKGROUND

Extended-release tacrolimus (TacER), administered once daily, offers improved adherence with reduced side effects while still maintaining an immunosuppressive potency equivalent to that of conventional tacrolimus preparations.

METHODS

The study included 83 patients who received consecutive living-donor kidney transplants at our facility from June 2013 to December 2016. Comparisons were made between 48 cases of induction with TacER and 35 cases of induction with cyclosporine (CyA). The observation period was 3 months after transplantation. Transplanted kidney function, rejection, infectious disease, lipid abnormalities, and glucose tolerance were compared.

RESULTS

The 2 groups showed no significant difference in donor background or transplanted kidney function. Within the 3-month observation period, an acute rejection response was observed in 2 cases in the TacER group and in 8 cases in the CyA group. After transplantation, hyperlipidemia requiring medication was observed more frequently in the CyA group. The 2 groups did not show a marked difference in systemic infection or renal calcineurin inhibitor toxicity in histopathologic examination of the transplanted kidneys 3 months after surgery.

DISCUSSION

Proactive use of TacER leads to improved adherence while yielding immunosuppressive potency equivalent to that of conventional tacrolimus preparations; however, tacrolimus has a potent blood sugar-elevating effect; thus, direct comparison with the CyA group is important for assessing the side effects.

CONCLUSION

TacER has the potential to also reduce side effects in the early stages after surgery, suggesting its potential as a drug of first choice.

Pathway level alterations rather than mutations in single genes predict response to HER2-targeted therapies in the neo-ALTTO trial

Background

We performed whole-exome sequencing of pretreatment biopsies and examined whether genome-wide metrics of overall mutational load, clonal heterogeneity or alterations at variant, gene, and pathway levels are associated with treatment response and survival.

Patients and Methods

Two hundred and three biopsies from the NeoALTTO trial were analyzed. Mutations were called with MuTect, and Strelka, using pooled normal DNA. Associations between DNA alterations and outcome were evaluated by logistic and Cox-proportional hazards regression.

Results

There were no recurrent single gene mutations significantly associated with pathologic complete response (pCR), except PIK3CA [odds ratio (OR) = 0.42, P = 0.0185]. Mutations in 33 of 714 pathways were significantly associated with response, but different genes were affected in different individuals. PIK3CA was present in 23 of these pathways defining a ‘trastuzumab resistance-network’ of 459 genes. Cases with mutations in this network had low pCR rates to trastuzumab (2/50, 4%) compared with cases with no mutations (9/16, 56%), OR = 0.035; P < 0.001. Mutations in the ‘Regulation of RhoA activity’ pathway were associated with higher pCR rate to lapatinib (OR = 14.8, adjusted P = 0.001), lapatinib + trastuzumab (OR = 3.0, adjusted P = 0.09), and all arms combined (OR = 3.77, adjusted P = 0.02). Patients (n = 124) with mutations in the trastuzumab resistance network but intact RhoA pathway had 2% (1/41) pCR rate with trastuzumab alone (OR = 0.026, P = 0.001) but adding lapatinib increased pCR rate to 45% (17/38, OR = 1.68, P = 0.3). Patients (n = 46) who had no mutations in either gene set had 6% pCR rate (1/15) with lapatinib, but had the highest pCR rate, 52% (8/15) with trastuzumab alone.

Conclusions

Mutations in the RhoA pathway are associated with pCR to lapatinib and mutations in a PIK3CA-related network are associated with resistance to trastuzumab. The combined mutation status of these two pathways could define patients with very low response rate to trastuzumab alone that can be augmented by adding lapatinib or substituting trastuzumab with lapatinib.