Declining use of inguinofemoral lymphadenectomy in the treatment of clinically negative, pathologic node positive vulvar cancer

PURPOSE

The management of vulvar cancer with clinically negative groin lymph nodes but with positive sentinel lymph node biopsy (SLNB) is controversial, with options including inguinofemoral lymphadenectomy (IFL) and/or adjuvant chemotherapy and radiotherapy. We used the National Cancer Database (NCDB) to examine trends in the management of clinically node negative, pathologically node positive (cN-/pN+) patients.

METHODS

The NCDB was used to identify cN-/pN+ vulvar cancer patients. Demographic and clinical data were compared with chi-squared and Wilcoxon rank-sum tests. OS was analyzed with the Kaplan-Meier method and log-rank test. Cox proportional hazards regression was used to determine factors associated with OS.

RESULTS

A total of 885 cN-/pN+ vulvar cancer patients were identified between 2012 and 2016, during which the rate of SLNB alone increased from 3.6% to 11.7%, while the rate of IFL +/- SLNB decreased from 89.7% to 78.1% (p < 0.05). Radiation was used in 68.5% and 64.6% of the SLNB-alone and IFL +/- SLNB cohorts, respectively, with chemoradiation in 37.1% and 33.6%, respectively. OS was not different between patients who received SLNB-alone vs. IFL +/- SLNB (p = 0.644). Receipt of chemotherapy and radiation was associated with improved OS (p < 0.001).

CONCLUSIONS

Among cN-/pN+ vulvar cancer patients in the NCDB, the practice of performing IFL decreased over time as SLNB-alone became more common and the majority received radiation +/- chemotherapy. There was no difference in OS between SLNB-alone vs. IFL +/- SLNB. Patients treated with adjuvant chemoradiation had improved survival. Whether the favorable outcomes in the SLNB-alone cohort may be attributed to radiotherapy dose escalation or use of chemotherapy warrants further study.

Early outcomes and patterns of failure following proton therapy for nonmetastatic intracranial nongerminomatous germ cell tumors

BACKGROUND

Although dosimetric comparisons demonstrate the advantage of proton therapy (PT) over conventional radiotherapy for nongerminomatous germ cell tumors (NGGCT), clinical outcome data for this rare tumor are lacking. We sought to evaluate outcomes for children with NGGCT treated with PT.

METHODS

Between 2007 and 2016, 14 children (median age 11, range, 5-19 years) with nonmetastatic NGGCT were treated with PT after induction chemotherapy. Most (8/14) were mixed germ cell. Five of 14 patients had complete resection of their primary tumor before radiation. Off study, eight patients received 36 Gy (RBE [relative biological effectiveness]) craniospinal irradiation (CSI). On study, two patients received 30.6 Gy (RBE) whole-ventricle irradiation and four received focal radiation alone. All patients received a total dose of 54 Gy (RBE) to the tumor/tumor bed.

RESULTS

At a median follow-up of 2.8 years, all patients were alive with no local recurrences. Three-year progression-free survival was 86%. Both metastatic recurrences occurred in patients treated with focal radiation alone; one with an immature teratoma developed an isolated spinal recurrence 5 months after treatment. Another with a mixed germ cell tumor developed a multifocal ventricular and shunt tract recurrence 7 months after treatment. Serious toxicity was minimal, including cataracts and hormone deficiency, and limited to children who received CSI.

CONCLUSION

Early outcomes in children treated for NGGCT suggest the high conformality of PT does not compromise disease control and yields low toxicity. This pattern of failure data adds to growing evidence suggesting chemotherapy followed by focal radiotherapy alone is inadequate in controlling localized NGGCT.

Abstract P1-10-13: Can the risk of radiation-induced cardiac disease in breast cancer be mitigated with cardiac-sparing techniques?

Introduction: Data suggest that long-term survivors of breast cancer treated with radiation therapy (RT) have an increased risk of cardiac events despite an overall survival benefit, particularly women with left-sided breast cancers. We hypothesized that with cardiac-sparing radiation techniques there would be no difference in long-term cardiac risks between women with right- and left-sided breast cancers.

Materials and Methods: The outcomes of 775 consecutive women treated between 1984 and 1999 with breast-conserving therapy (BCT) (n=424) and post-mastectomy radiation therapy (PMRT) (n=351) for stage 0-3 breast cancer were assessed retrospectively through a review of medical records and contact with living patients. The choice of BCT vs PMRT was based on tumor board disposition and patient preference; mastectomy was recommended for multicentric or T3 breast cancers. Ninety-six percent of all node-positive patients received treatment to all nodal regions, including the internal mammary (IM), axillary (AX), and supraclavicular (SC) nodes. BCT patients had computed tomography-planned tangential breast radiation with photons with IM nodes treated within the tangent fields or with a separate en face electron field to minimize cardiac exposure. PMRT patients were treated with en face electron fields for the chest wall and IM for sparing of the lung and heart. The AX and SC nodes were treated with a matched anterior photon field with a posterior-anterior boost field (PAB) when necessary to achieve adequate dose in the AX with both BCT and PMRT. Overall, 411 patients were node-negative and 353 were node-positive. All patients have a minimum potential follow-up of 16.4 years; median actual follow-up for the BCT group was 15 years (range, 0.1-31.2) and for the PMRT group it was 9.5 years (range, 0.1-30.5).

Results: Overall survival (OS), cause-specific survival (CSS), and freedom from local-regional recurrence (FFLR) rates for the cohort at 15 years were 58.2%, 72.0%, and 90.8%, respectively. Rates of freedom from cardiac events (FFCE), pulmonary events, and second malignancy were 87.6%, 93.6%, and 86.3%, respectively. On multivariate analysis, OS was correlated with stage (p=.045), number of positive nodes (p=.002), age (p&lt;.0001), diabetes (p =.0021), and modality (p=.0017). Not surprisingly, 15-year survival for patients treated with BCT was better than for patients treated with PMRT (70.9% vs 59.7%; p&lt;.0001). CSS was associated with stage (p=.0207), number of positive nodes (p=.0409), and modality (p=.0003). FFLR was associated with number of positive nodes (p=.0484). FFCE was associated with pretreatment cardiac disease (p&lt;.0001), stage (p=.0461), and age (p=.0056), but not with either breast cancer laterality (p=.1906) or modality (BCT vs PMRT; p=.7487).

Discussion: Long-term disease control and survival outcomes were better in BCT than PMRT patients, likely due to selection criteria. Cardiac events were associated with pretreatment heart disease, older age, and stage, suggesting that this population may benefit from advanced radiation techniques that can further limit cardiac dose. Neither breast cancer laterality nor treatment modality was associated with cardiac events.

Citation Format: Smith TL, Mokhtech M, Bradley JA, Lightsey JL, Morris CG, Mendenhall NP. Can the risk of radiation-induced cardiac disease in breast cancer be mitigated with cardiac-sparing techniques? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-10-13.