diagnosed with ovarian peritoneal cancer; she doesn't feel well but doesn't know if that feeling is due to the cancer or chemotherapy; felt yucky; first two doses of the Moderna COVID-19 vaccine on 30SEP2021 and 11NOV2021; had arm pain after 2nd dose; This spontaneous case was reported by a consumer and describes the occurrence of OVARIAN CANCER STAGE IV (diagnosed with ovarian peritoneal cancer) in an 81-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 039F21A and 049E21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Patient was not tested/diagnosed positive for COVID-19.  Concurrent medical conditions included Penicillin allergy, Allergy to antibiotic (allergic to Keflex), Allergy to chemicals (Allergic to Sulfur) and Chemical sensitivity (environmental sensitivity to different chemicals). Concomitant products included COLECALCIFEROL (VITAMIN D3), ZINC PICOLINATE, MAGNESIUM L-THREONATE (MAGTEIN), MAGNESIUM TAURATE, MAGNESIUM GLYCINATE and FYTATE CALCIUM MAGNESIUM (CELL FORTE IP-6 & INOSITOL) for an unknown indication.   On 30-Sep-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .5 milliliter. On 11-Nov-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to .5 milliliter. On 11-Nov-2021, the patient experienced VACCINATION SITE PAIN (had arm pain after 2nd dose) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (first two doses of the Moderna COVID-19 vaccine on 30SEP2021 and 11NOV2021). On 12-Nov-2021, the patient experienced FEELING ABNORMAL (felt yucky). In February 2022, the patient experienced OVARIAN CANCER STAGE IV (diagnosed with ovarian peritoneal cancer) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced MALAISE (she doesn't feel well but doesn't know if that feeling is due to the cancer or chemotherapy). The patient was hospitalized from 17-Feb-2022 to 01-Mar-2022 due to OVARIAN CANCER STAGE IV. The patient was treated with CARBOPLATIN for Ovarian cancer, at an unspecified dose and frequency; LIDOCAINE (LIDOCAIN [LIDOCAINE]) for Cancer pain and Postoperative pain, at an unspecified dose and frequency; IBUPROFEN (MOTRIN [IBUPROFEN]) for Cancer pain and Postoperative pain, at an unspecified dose and frequency; PACLITAXEL (TAXOL) for Ovarian cancer, at an unspecified dose and frequency and Surgery for Ovarian cancer stage IV. On 16-Nov-2021, VACCINATION SITE PAIN (had arm pain after 2nd dose) and FEELING ABNORMAL (felt yucky) had resolved. At the time of the report, OVARIAN CANCER STAGE IV (diagnosed with ovarian peritoneal cancer) had not resolved and MALAISE (she doesn't feel well but doesn't know if that feeling is due to the cancer or chemotherapy) and INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (first two doses of the Moderna COVID-19 vaccine on 30SEP2021 and 11NOV2021) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In October 2021, Weight: lost 18 pounds lost 18 pounds since fall 2021. In February 2022, Carbohydrate antigen 125: 1125 1125. On an unknown date, Carbohydrate antigen 125: 99 99, 19 19 and 8 8.     Concomitant medications included high dosage probiotic.  Patient was diagnosed with stage 4, Ovarian peritoneal cancer in Feb 2022. Patient said that she probably had the cancer for a while, but it was diagnosed more recently. Patient was hospitalized on17-Feb-2022 for surgery of ovarian cancer, patient had an incision going from under her heart to the bladder. Patient had a major surgery for the cancer in Feb2022 and was getting infusions to treat the cancer. She had received 2 infusions and would be getting a 3rd one in 2 weeks. Patient said that the chemotherapy she was receiving with Taxol and Carboplatin was working well because her CA-125 marker has decreased significantly since she started the infusions. Her CA-125 was 1125 in Feb 2022. Before she started chemotherapy, it fell to 99 and the last two times it fell even more to 19 and 8, respectively.  She also stated that she had arm pain after the 1st and 2nd dose of the Moderna COVID-19 vaccine. The pain lasted for 4-5 days. She received the shots on her right arm but couldn't remember which arm experienced the pain. She also felt yucky for 2 to 3 days after receiving both doses of the Moderna vaccine. She stated that she had lost 18 lbs since fall 2021. Treatment medications included Homeopathic T-relief for pain associated with the cancer surgery and/or the disease itself. Caller wanted to know if she could receive the full dose for her 3rd dose or half dose of Moderna. She also wanted to know if there were any potential interactions between her chemotherapy treatment and the Moderna vaccine.  Company comment: This spontaneous case concerns an 81-year-old, female patient with no reported relevant medical history, who experienced the unexpected, serious (hospitalized, medically significant) event of Ovarian cancer stage IV, with non-serious event of Malaise. Inappropriate schedule of product administration was reported as an additional event wherein the patient received mRNA-1273 as primary series with dosing interval of 42 days - not within the recommended window period. Other non-serious events were also experienced immediately after vaccination and were reported resolved within a week post-vaccination. The serious event was diagnosed approximately 3 months after receiving the second dose of mRNA-1273, with CA-125 value of 1125; although the patient already observed weight loss even prior to diagnosis. Other presenting symptoms with onset dates were not provided in the case. The patient underwent an unspecified surgery after diagnosis and is now receiving chemotherapy with Taxol and Carboplatin, with note of improving tumor marker after initiation of treatment. The elderly age of the patient could be considered a risk factor for the gynecologic malignancy. The benefit-risk relationship of mRNA-1273 is not affected by this report.    This case was linked to MOD-2022-568750.; Sender's Comments: This spontaneous case concerns an 81-year-old, female patient with no reported relevant medical history, who experienced the unexpected, serious (hospitalized, medically significant) event of Ovarian cancer stage IV, with non-serious event of Malaise. Inappropriate schedule of product administration was reported as an additional event wherein the patient received mRNA-1273 as primary series with dosing interval of 42 days - not within the recommended window period. Other non-serious events were also experienced immediately after vaccination and were reported resolved within a week post-vaccination. The serious event was diagnosed approximately 3 months after receiving the second dose of mRNA-1273, with CA-125 value of 1125; although the patient already observed weight loss even prior to diagnosis. Other presenting symptoms with onset dates were not provided in the case. The patient underwent an unspecified surgery after diagnosis and is now receiving chemotherapy with Taxol and Carboplatin, with note of improving tumor marker after initiation of treatment. The elderly age of the patient could be considered a risk factor for the gynecologic malignancy. The benefit-risk relationship of mRNA-1273 is not affected by this report.