Patients who have received any prior chemotherapy are not eligible Patients who have received any prior cytotoxic chemotherapy or biologics for sex cord-stromal tumors (SCSTs) Patients diagnosed with Ewing Sarcoma as a second malignant neoplasm are not eligible if they have received chemotherapy or radiation for the treatment of their primary malignancy Patients who have received prior chemotherapy for any abdominal or pelvic tumor including neo-adjuvant chemotherapy for their ovarian or primary peritoneal cancer are excluded; patients may have received prior adjuvant chemotherapy for localized breast cancer, provided that it was completed more than three years prior to registration, and that the patient remains free of recurrent or metastatic disease Patients must not have received prior chemotherapy, radiotherapy, or antibody therapy for lymphoma Patients who have received prior pelvic radiation or cytotoxic chemotherapy Patients that are receiving or have received chemotherapy regimens are allowed Patients who have received any prior cytotoxic chemotherapy for the current diagnosis of ALCL or any cancer diagnosed previously are not eligible Patients must NOT have received prior chemotherapy or targeted therapy, including chemotherapy used for radiation sensitization for treatment of endometrial carcinoma Patients must not have received previous systemic cytotoxic chemotherapy for urothelial carcinoma No concurrent treatment with other cytotoxic drugs or targeted therapies Patients who have received treatment with any other cytotoxic chemotherapy prior to beginning protocol therapy (other than allowed in above criteria) are excluded Patients are allowed to have received up to three prior cytotoxic regimens for treatment of their epithelial ovarian, fallopian tube, or primary peritoneal cancer; they must have had one prior platinum-based chemotherapeutic regimen for management of primary disease, possibly including intra-peritoneal therapy, consolidation, biologic/targeted (non-cytotoxic) agents or extended therapy (maintenance/consolidation) administered after surgical or non-surgical assessment; patients are allowed to have received, but are not required to have received, one to two cytotoxic regimens for management of recurrent or persistent disease; (for the purposes of this study poly adenosine diphosphate [ADP] ribose polymerase [PARP] inhibitors given for recurrent or progressive disease will be considered cytotoxic; PARP inhibitors given as maintenance therapy in continuation with management of primary disease will not be considered as a separate cytotoxic regimen); if two cytotoxic regimens had been received for management of recurrent or persistent disease, one of these regimens would have had to contain either a platinum or a taxane agent Patients who have received prior chemotherapy for any abdominal or pelvic tumor OTHER THAN for the treatment of ovarian, fallopian tube, or primary peritoneal cancer within the last three years are excluded; patients may have received prior adjuvant chemotherapy and radiotherapy for localized breast cancer, provided that it was completed more than 2 years prior to registration, and the patient remains free of recurrent or metastatic disease and hormonal therapy has been discontinued; patients who have received prior radiotherapy to any portion of the abdominal cavity or pelvis or thoracic cavity within the last three years are excluded; prior radiation for localized cancer of the head and neck or skin is permitted, provided that it was completed more than three years prior to registration, and the patient remains free of recurrent or metastatic disease Planned cytotoxic chemotherapy during the WBRT only; patients may have had prior chemotherapy Participants for whom front-line cytotoxic therapy is indicated (i.e. symptomatic visceral or pulmonary KS or symptomatic KS impairing functional status) Patients may not have received any of the protocol agents within 5 years prior to randomization No prior cytotoxic chemotherapy for metastatic disease; prior immunotherapy is permitted Patients who have received any chemotherapy (excluding steroids) and/or RT prior to this enrollment Kaposi sarcoma (KS) (following prior KS-specific therapy (Cohorts 1-3)* (KS) impacting physical and/or psychological wellbeing and not amenable to local therapy and one or more of the following: ** Stable KS despite 6 or more cycles of liposomal doxorubicin or paclitaxel or other active cytotoxic agents (i.e. etoposide, bleomycin, anthracyclines, vincristine [vincristine sulfate], vinblastine); or** Progressive disease despite 3 or more cycles of liposomal doxorubicin or paclitaxel or other active cytotoxic agents (i.e. etoposide, bleomycin, anthracyclines, vincristine, vinblastine); or** Patient who received a cumulative lifetime dose of anthracycline of >= 550 mg/m^2; or** Recurrent or progressive KS after completion of prior first line chemotherapy** Intolerant of or refuses further cytotoxic chemotherapy** No KSHV-associated multicentric Castleman disease in past 5 years** For KS patients, the following laboratory values supersede values below:*** Platelets > lower limit of normal*** Hemoglobin > 10 g/dL Treatment naive Kaposi sarcoma impacting physical and/or psychological wellbeing and not amenable to local therapy. (Cohort 4)* On antiretroviral therapy (ART) with suppressed HIV viral load for > 3 months (Note: an extended washout period is needed to avoid treatment during the period of risk for the highly toxic and often fatal Immune Reconstitution Inflammatory Syndrome (IRIS)* No KSHV-associated multicentric Castleman disease in past 5 years* No prior systemic chemotherapy * No symptomatic pulmonary KS or chest X-rays positive for un-evaluated abnormalities * Disease evaluable by AIDS Clinical Trial Group (ACTG) KS response criteria* CD4+ T-cell count >= 100 cells/uL * For KS patients, the following laboratory values supersede values below:** Platelets > lower limit of normal** Hemoglobin > 10 g/dL Patients must have had =< 1 prior cytotoxic regimen for metastatic disease (unless enrolling in the Progressive Brain Metastases Cohort); note that endocrine and immunotherapies do not count as cytotoxic regimens Patients must not have received prior irinotecan-based chemotherapy (e.g. irinotecan hydrochloride, leucovorin calcium, fluorouracil, and oxaliplatin [FOLFIRINOX] or FOLFIRI) Biopsy-proven KS involving skin (with or without visceral involvement) without need for urgent cytotoxic therapy; there should be no evidence of improvement in KS in the 4 weeks immediately prior to study enrollment Participant may be either previously untreated for KS or refractory to or intolerant of any one or more prior KS therapies Patients who have received prior chemotherapy for any abdominal or pelvic tumor within the last three years are excluded; patients may have received prior adjuvant chemotherapy and radiotherapy for localized breast cancer, provided that it was completed more than 2 years prior to registration, the patient remains free of recurrent or metastatic disease and hormonal therapy has been discontinued Prior therapy requirements:* Wt-GIST: previously untreated participants are eligible* PHEO/PGL with germline SDH subunit mutation: 131I-methyl-iodobenzylguanine (MIBG) in patients with MIBG avid tumors or cytotoxic chemotherapy (cyclophosphamide, vincristine, and dacarbazine [CVD] or temozolomide) is required prior to enrollment on this trial; however, patients who have refused cytotoxic chemotherapy or for whom treatment on this protocol prior to receiving cytotoxic chemotherapy is felt to be in the best interest for the patient by the local investigator will also be eligible* HLRCC-associated renal cell cancer: previously untreated participants are eligible ALL developing after a previous cancer treated with cytotoxic chemotherapy Has received prior cisplatin- or carboplatin-based chemotherapy regimen for malignancy including diagnoses other than germ cell tumor Planned use of cytotoxic chemotherapy during radiation (only adjuvant temozolomide therapy will be used on this protocol)