Ductal carcinoma/Booster shot may have jump started cancer; Three little specks and one nodule in the lung; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team, Program ID:. The reporter is the patient.  A 73-year-old female patient received BNT162b2 (BNT162B2), as dose 3 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "bilateral mastectomy" (not ongoing), notes: 25 years ago; "stage 4 breast cancer" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (Primary immunization series completed; unknown manufacturer), for COVID-19 Immunization. The following information was reported: PULMONARY MASS (non-serious) with onset 02Nov2022, outcome "unknown", described as "Three little specks and one nodule in the lung"; BREAST CANCER RECURRENT (medically significant), outcome "unknown", described as "Ductal carcinoma/Booster shot may have jump started cancer". The events "ductal carcinoma/booster shot may have jump started cancer" and "three little specks and one nodule in the lung" required physician office visit. The patient underwent the following laboratory tests and procedures: Biopsy: (unspecified date) ductal carcinoma; (unspecified date) three little hard bumps in her armpit, notes: that was cancer, had three little specks and one nodule in the lung; Computerised tomogram: (unspecified date) did not show anything; (unspecified date) three little hard bumps in her armpit, notes: that was cancer, had three little specks and one nodule in the lung; (30Jan2023) three little specks are gone; Positron emission tomogram: (unspecified date) cancer; (02Nov2022) three little specks and one nodule in the lung; Ultrasound scan: (unspecified date) soft tissue swelling; (unspecified date) three little hard bumps in her armpit, notes: that was cancer, had three little specks and one nodule in the lung; (unspecified date) did not show anything. Therapeutic measures were taken as a result of breast cancer recurrent. Clinical course: Patient stated that she had stage 4 breast cancer and received the Covid booster shots before and wanted to know if it interfered with her taking Ibrance, patient stated she asked her provider but no one knew. She talked to her oncologist that told her to get the 3rd booster as she already had 2 boosters. She had not noticed any difference at all after getting it. She was approved to get an extra month since she was going on vacation. She was wondering if the booster jumpstarted this cancer but nobody could say for sure. She had a bilateral mastectomy 25 years ago. After the 2nd booster shot she had swelling under her arm, it was not on the lymph node as it was on the front part of arm, that was soft tissue. She did an ultrasound at her local hospital and they said it was just soft tissue swelling. She stated that it did not go away so a couple of months later she did another ultrasound with the same thing and then did a CAT Scan that did not show anything. She stated this was all over a 9 month period. Her doctor sent her to the main hospital 100 miles away where the radiologist said there was definitely something there. They then did a biopsy that came back as ductal carcinoma. They then had her do a PET Scan and it showed up as cancer. She had 3 little hard bumps in her armpit which is cancer. She also had 3 little specs and 1 nodule in the lungs. After 2 months of Ibrance, the swelling in the front part of her arm that budged out was gone, the 4 little hard lumps are 1/10th the size they used to be and the specs in her lungs are gone. She states the Ibrance was working. Additional Context: Warm transfer from NTID: (Name withheld)  Pfizer Medical Information: INT-#. Mentioned that she had the Covid 19 booster today and had already had two boosters before that one. Mentioned that after the second booster shot that she had swelling on front part of her arm that was soft tissue which was diagnosed as cancer. Believes that the booster shot may have jump started cancer. After the swelling, they did an ultrasound, CAT scan and biopsy. Stated that they showed that she had three little hard bumps in her armpit that was cancer, had three little specks and one nodule in the lung. After two months of Ibrance, the swelling in her arm was gone and specks in her lungs were also gone. Information confirmed as provided. Clarified that the bumps in her armpit still there were like marbles before and are now like little nubbies not like they were before. Later clarified that this happened after the first booster shot. Mentioned that her doctor stated that the booster shot had nothing to do with the cancer and that the doctor that did the biopsy seemed to think that it could have. Guessed that nobody seemed to know. Had a PET scan on 02Nov2022 and the three little specks and one nodule in the lung showed up on it. Started taking Ibrance on 01Dec2022. Has no side effects from Ibrance and it is working.  The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202300107377 same patient, different drug/event;US-PFIZER INC-202300108892 Same patient and product, different dose and event;