Genetic landscape of indolent and aggressive Kaposi sarcomas

BACKGROUND

Kaposi sarcoma (KS) is a rare skin tumour caused by herpesvirus 8 infection and characterized by either indolence or an aggressive course necessitating systemic therapies. The genetic basis of this difference remains unknown.

OBJECTIVES

To explore the tumour mutational burden in indolent and aggressive KS.

METHODS

We performed whole-exome sequencing on a cohort of 21 KS patients. We compared genetic landscape including tumor mutational burden between the two forms of indolent and agressive KS.

RESULTS

Aggressive KS tumours had a significantly higher TMB and a larger cumulative number of deleterious mutations than indolent KS tumours. In addition, all aggressive tumours had at least three deleterious mutations, whereas most indolent tumours harboured only one or no predicted deleterious mutations. Deleterious mutations listed in the Cancer Gene Census were detected exclusively in patients with aggressive disease. An analysis of somatic copy-number alterations (SCNA) revealed a tendency towards higher number of alterations in aggressive KS.

CONCLUSIONS

These data suggest that SCNA alterations and an increase in mutational burden promote aggressive KS and that it might be more appropriate to consider indolent KS as an opportunistic skin disease rather than a cancer.

P2597Heart failure and atrial tachyarrhythmia on abiraterone: a characterization using pharmacovigilance databases

Background

Abiraterone and enzalutamide are recently approved androgen deprivation therapies (ADT) for metastatic prostate cancer. The cardiac safety profile for the two drugs is unknown.

Methods

Using French and World Health Organization (WHO) pharmacovigilance databases, we performed a disproportionality-analysis of suspected adverse-drug-reactions (ADR) to evaluate the reporting-odds-ratio (ROR) of cardiac ADR associated with abiraterone compared to enzalutamide, other ADT used in prostate cancer, and entire database. Clinical and demographic characterization of patients with ADT-induced cardiac ADR was performed.

Results

In the 5,759,781 ADR reports in men, 55,070 pertained to ADT. The ROR of AT for abiraterone was of 4.1 [3.1–5.3] vs. enzalutamide, 3.7 [3–4.5] vs. other ADT, and 3.2 [2.7–3.7] vs. entire database. The corresponding ROR for HF were of 2.5 [2–3], 1.5 [1.3–1.7], and 2 [1.7–2.3], respectively. Mean time to AT and HF onset was shorter on abiraterone (5.2±0.8 and 4.5±0.6 months, respectively) vs. other ADT (13.3±3.2 and 9.2±1.1 months; p<0.05). Cases on abiraterone vs. other ADT were more frequently associated with ≥2 ADR-terms including AT, HF, hypokalemia, hypertension and edema (13.6% vs. 6%, p<10–4). For abiraterone, age but not dose was associated to reporting of AT/HF vs. any other ADR.

Table 1 Number (available data) AT HF Hypokalemia Edema Hypertension Age (y) 5989 r: 0.03, p: 0.02 r: 0.05, p≤0.0001 r: 0.06, p≤0.0001 r: 0.04, p≤0.01 ns Dose of hydrocortisone equivalent (mg/day) 3828 ns ns ns r: −0.07, p≤0.001 r: −0.12, p≤0.0001 Dose of abiraterone (mg/day) 6285 ns ns ns ns ns Details concerning correlation (r) between clinical covariates and reporting for AT, HF, hypokalemia, edema and hypertension within overall adverse drug reaction on abiraterone (n: 9203) extracted from VigiBase (through 08/2017).

Time to onset

Conclusion

Compared to other ADT, abiraterone was associated with a higher reporting of AT and HF associated with hypokalemia, hypertension and edema. These findings are consistent with the hyper-mineralocorticism induced by abiraterone and not with other ADT.

Impact of adjuvant treatment modalities on the management of patients with stages I-II endometrial stromal sarcoma

PURPOSE

To explore whether adjuvant treatment options may impact on the prognosis in localized endometrial stromal sarcomas (ESSs; stages I and II). The historical options usually discussed in addition to hysterectomy and bilateral salpingoophorectomy (BSO) are active surveillance, pelvic radiotherapy, chemotherapy and hormonal therapy, alone or in combination.

PATIENTS AND METHODS

Among 84 consecutive patients treated for ESS at a single referral center, 54 with localized stage disease were identified. Recurrence-free survival and overall survival were estimated and patterns of recurrences described. Univariate and multivariate analyses were carried out.

RESULTS

With a median follow-up of 58 months, only one patient had died. None of the 23 patients who had received adjuvant therapy relapsed compared with 13 of 31 patients who had not received any adjuvant therapy. Adjuvant treatments were hormonal therapy (n = 10) and brachytherapy with/without pelvic radiotherapy (n = 13). Almost the majority of relapses were local (92%) and extra-pelvic metastasis was observed in nearly half of the patients (46%). In the multivariate analysis, the major determinants of relapse-free survival were adjuvant treatment, myometrial invasion (P = 0.005) and no BSO (P = 0.005).

CONCLUSIONS

In this series, adjuvant treatment of localized ESSs was associated with the absence of recurrence.