Investigation of Circulating Tumor Cells From Cancer Patients Undergoing Radiation Therapy

Inclusion Criteria: * Histologically confirmed cancer, fitting one of the following cohorts: locally advanced head and neck cancer but no distant metastasis scheduled to receive radiotherapy to the head and neck region with or without chemotherapy/targeted therapy (palliative or curative intent); locally advanced cervical cancer without distant metastasis scheduled for radiotherapy to the pelvic region with or without chemotherapy/targeted therapy (palliative or curative intent); Stage I to III non-small cell lung cancer, without distant metastasis, scheduled to receive stereotactic body radiotherapy for early stage lung disease and/or external beam radiotherapy for locally advanced lung disease, with or without concurrent/sequential chemotherapy and/or targeted therapy (curative intent); metastatic prostate cancer scheduled for palliative radiotherapy, or biochemically recurrent prostate cancer following radical prostatectomy; scheduled for salvage prostatic fossa radiotherapy, with or without androgen deprivation or with high risk prostate cancer; locally advanced rectal cancer (no distant metastasis) scheduled to receive neoadjuvant chemoradiotherapy (curative intent); oligometastatic cancer, defined as any solid malignancy with\< 5 measurable sites of metastatic disease, limited to a maximum of 3 anatomic organ systems, excluding the primary tumor and regional lymph nodes. At least 1 site of metastatic disease, but as many as all 5 sites, in addition to the primary tumor and regional lymph nodes, is amenable to local ablative therapy with external beam radiation, stereotactic cranial radiosurgery (SRS) or stereotactic body radiotherapy (SBRT). Treatment will be guided by multi-disciplinary evaluation and may also include surgery, chemotherapy or target agents at the discretion of the primary oncologists. Patients may present with oligometastatic disease or have oligometastatic disease recurrence after definitive therapy for localized disease; Melanoma or metastatic NSCLC scheduled to receive ipilimumab, nivolumab, and/or pembrolizumab.; Locally advanced head and neck cancer (HNSCC) scheduled to receive induction chemotherapy followed by radiotherapy; Metastatic breast cancer scheduled to receive any treatment, including radiation therapy and/or systemic/hormonal therapy; Stage III endometrial cancer scheduled to receive radiation therapy * Scheduled to initiate radiation for management of their disease, and schedule accommodates blood sample collection prior to radiation * Male and female of ≥18 years of age * Male and female patients capable of reproduction must agree to use medically acceptable methods of contraception, such as an intra-uterine device, diaphragm with spermicide, condom with spermicide, or abstinence during radiation therapy. Inclusion of females of childbearing potential requires a negative pregnancy test within 14 days prior to study initiation (part of standard of care in radiation oncology). * Written informed consent obtained and signed * Able to have blood collection without excessive difficulty Exclusion Criteria: * Patient unwilling or unable to complete informed consent * Physical or psychological inability to complete sample collection for any reason including but not limited to: inability to tolerate any study procedures, any physical limitation that would undermine the safety of the subject in the study, or any psychiatric or neurological condition that inhibits full comprehension of study requirements and inability to complete informed consent, as determined by treating physician * Currently pregnant or lactating women