This study is being done to answer the following questions: Is the chance of rectal cancer responding the same if chemotherapy alone is given before limited surgery compared to chemotherapy and radiation therapy given together before limited surgery? If radiation therapy is not given, is quality of life better?

This phase III trial compares the effect of adding cemiplimab to standard therapy (surgery with or without radiation) versus standard therapy alone in treating patients with stage III/IV squamous cell skin cancer that is able to be removed by surgery (resectable) and that may have come back after a period of improvement (recurrent). The usual treatment for patients with resectable squamous cell skin cancer is the removal of the cancerous tissue (surgery) with or without radiation, which uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Immunotherapy with monoclonal antibodies, such as cemiplimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Cemiplimab has been approved for the treatment of skin cancer that has spread or that cannot be removed by surgery, but it has not been approved for the treatment of skin cancer than can be removed by surgery. Adding cemiplimab to the usual treatment of surgery with or without radiation may be more effective in treating patients with stage III/IV resectable squamous cell skin cancer than the usual treatment alone.

This phase I/II trial studies the safety, side effects and best dose of M3814 and to see how well it works when given together with radiation therapy in treating patients with pancreatic cancer that has spread to nearby tissue or lymph nodes (locally advanced). M3814 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Hypofractionated radiation therapy delivers higher doses of radiation therapy over a shorter period of time and may kill more tumor cells and have fewer side effects. Giving M3814 and hypofractionated radiation therapy together may be safe, tolerable and/or more effective than radiation therapy alone in treating patients with locally advanced pancreatic cancer.

This phase I/II trial studies the side effects, safety, and effectiveness of low dose radiation to the entire body (total body irradiation \[TBI\]) and higher dose radiation to known areas of cancer (hypofractionated radiation therapy \[H-RT\]) combined with atezolizumab and chemotherapy (carboplatin \& etoposide) in treating patients with small cell lung cancer that has spread to disease sites outside of the lung (extensive stage). Extensive stage disease has historically been treated with chemotherapy alone with consideration of chest (thoracic) radiation therapy for those with response to chemotherapy, as well as consideration of preventative radiation therapy to the head (prophylactic cranial irradiation). Emerging evidence supports the synergistic interactions between immunotherapy and radiation therapy. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Carboplatin is in a class of medications known as platinum-containing compounds. It works in a way similar to the anticancer drug cisplatin, but may be better tolerated than cisplatin. Carboplatin works by killing, stopping or slowing the growth of tumor cells. Etoposide is in a class of medications known as podophyllotoxin derivatives. It blocks a certain enzyme needed for cell division and DNA repair and may kill tumor cells. Combining TBI and H-RT with atezolizumab and chemotherapy may improve response to treatment.

This phase III trial compares the effect of adding immunotherapy (brentuximab vedotin and nivolumab) to standard treatment (chemotherapy with or without radiation) to the standard treatment alone in improving survival in patients with stage I and II classical Hodgkin lymphoma. Brentuximab vedotin is in a class of medications called antibody-drug conjugates. It is made of a monoclonal antibody called brentuximab that is linked to a cytotoxic agent called vedotin. Brentuximab attaches to CD30 positive lymphoma cells in a targeted way and delivers vedotin to kill them. A monoclonal antibody is a type of protein that can bind to certain targets in the body, such as molecules that cause the body to make an immune response (antigens). Immunotherapy with monoclonal antibodies, such as nivolumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Chemotherapy drugs such as doxorubicin hydrochloride, bleomycin sulfate, vinblastine sulfate, dacarbazine, and procarbazine hydrochloride work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Cyclophosphamide is in a class of medications called alkylating agents. It works by damaging the cell's deoxyribonucleic acid (DNA) and may kill cancer cells. It may also lower the body's immune response. Etoposide is in a class of medications known as podophyllotoxin derivatives. It blocks a certain enzyme needed for cell division and DNA repair and may kill cancer cells. Vincristine is in a class of medications called vinca alkaloids. It works by stopping cancer cells from growing and dividing and may kill them. Prednisone is in a class of medications called corticosteroids. It is used to reduce inflammation and lower the body's immune response to help lessen the side effects of chemotherapy drugs. Radiation therapy uses high energy x-rays to kill tumor cells and shrink tumors. Adding immunotherapy to the standard treatment of chemotherapy with or without radiation may increase survival and/or fewer short-term or long-term side effects in patients with classical Hodgkin lymphoma compared to the standard treatment alone.

This phase I trial tests the safety, side effects, and best dose of triapine in combination with radiation therapy in treating patients with glioblastoma or astrocytoma that has come back after a period of improvement (recurrent). Triapine may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Giving triapine in combination with radiation therapy may be safe, tolerable, and/or effective in treating patients with recurrent glioblastoma or astrocytoma.