cancer has moved to her lymph nodes/ cancer went into the lymph system in her chest; lung tumor doubled in size/tumor was measured at 3.8 and then it went to 8 so that doubled in size; This is a spontaneous report from a contactable consumer (patient's husband). A 73-year-old female patient received BNT162B2 (Pfizer Covid 19 mRNA vaccine, solution for injection, Batch/Lot Number: EP7534), via an unspecified route of administration, administered in Arm Right on 29Mar2021 (age at vaccination 73-years-old), as DOSE 2, SINGLE for covid-19 immunisation. Medical history included ongoing small cell lung cancer, allergy to penicillin when she was very young. Her mother told her never to take the penicillin because she was allergic to it. NDC/Lot/Expiry not known, that was probably 65 years ago. She also had a few surgeries. The patient's concomitant medications were not reported. No additional vaccines was administered on same date of the Pfizer suspect. List of any other vaccinations within four weeks prior to the first administration date of the suspect vaccine was reported as none. On 08Mar2021, patient received BNT162B2 (Pfizer Covid 19 vaccine, solution for injection, Batch/Lot Number: EN6199), dose 1 via an unspecified route of administration, administered in Arm Right as DOSE 1, SINGLE for covid-19 immunisation. He reported that he and his wife both got their Covid 19 vaccines, the second dose on 29Mar2021. He stated his wife had small cell carcinoma of the lung, lung cancer and she had a CAT scan done recently and the CAT scan showed that the cancer had moved to her lymph nodes and she will be doing chemotherapy treatments. He stated her doctor will be using a "smart drug", Keytruda. He stated her lung tumor actually doubled in size and went into the lymph system in her chest. His concern was, his wife would like to get her Covid 19 booster but because she had to do the chemotherapy he didn't know if their was any information on chemotherapy and the Covid 19 vaccine. He stated the chemotherapy was designed to target his wife's immune system and from what he understood, the Covid 19 vaccine also targets the immune system. After the second Covid 19 vaccine, on an unspecified date the cancer moved to her lymph nodes and the lung tumor doubled in size. He did not said that the Covid 19 vaccine caused this. The Patient was taken to physician office as her lung tumor doubled in size. It was reported that he talked to his wife's oncologist and because the cancer had moved into her lymph system the doctor wanted to begin treatment right away. The doctor stated to the caller that he didn't believe that the Covid 19 booster would affect her taking the chemotherapy but he really didn't know. He would like someone at Pfizer to say the Covid 19 vaccine has been given out for a year and some of those people who have received the Covid 19 vaccine might have ongoing immunotherapy. He stated it didn't seem that those people have problems. He wanted to be safe and his wife will have to have the chemotherapy treatment starting in the next 2 to 3 days (unspecified date). He clarified that his wife had not begun her chemotherapy treatment yet. He provided the names of the chemotherapy medications that his wife will receive as Keytruda, Carboplatin, and Alimta. He reported that his wife had some blood work, CAT scan, and PET scan done on unspecified date. He stated that his wife put off doing any CAT scans right away because they were withheld and everyone was sick with the Covid 19 virus right now. The CAT scan showed the area in her lower left lobe had doubled in size from her CAT scan a year ago. He thought the tumor was measured at 3.8 and then it went to 8 so that doubled in size. It was reported that he doesn't know the measurement specifics. At the time of this report, the outcome of event lung tumor doubled in size/tumor was measured at 3.8 and then it went to 8 so that doubled in size and cancer has moved to her lymph nodes/ cancer went into the lymph system in her chest was unknown.  Follow-up attempts are completed. No further information is expected.