Persistent low-grade fever during chemo + immunotherapy for stage IV NSCLC — has anyone experienced something similar?
Hi everyone, I’m writing about my mother, who is 56 and has stage IV non-small cell lung adenocarcinoma with metastases to bone, adrenal gland, lymph nodes.
She is currently receiving a combination of chemotherapy and immunotherapy.
Over the last several days she has developed a persistent low-grade fever, usually around 37.5–38.0°C (99.5–100.4°F). What is strange is that, overall, she feels relatively well. She does not look seriously ill and has not had major chills or a significant deterioration in her general condition.
The fever actually started the day before her most recent immunotherapy infusion, so it wasn’t simply an immediate infusion reaction. She has also had muscle aches/pain in both legs and at one point some pain in her right flank, which was evaluated and considered possibly a renal colic.
Recent blood tests were fairly reassuring:
WBC: 5.8 ×10³/µL
Absolute neutrophils: 4.4 ×10³/µL
Neutrophils: 76.4%
Lymphocytes: 0.9 ×10³/µL
Platelets: 257 ×10³/µL
Hemoglobin: 12.6 g/dL
Creatinine: 0.47 mg/dL
Bilirubin: normal
AST/GOT: 56 U/L
ALT/GPT: 72 U/L
CRP was around 0.9 mg/dL / 9 mg/L
So at the time of the blood tests she was not neutropenic, and there was no obvious major organ dysfunction, although her liver enzymes were mildly elevated.
We obviously know that infection still has to be ruled out even with normal white blood cells/neutrophils, especially in a cancer patient. We are also wondering whether this could be an inflammatory/immune-related effect of immunotherapy, since she is also having muscle aches and mild liver enzyme elevation.
The possibility that scares us is neoplastic/tumor fever, although I understand that this is generally considered only after infections and treatment-related causes have been excluded.
I’m not asking Reddit for a diagnosis — her oncology team is following her — but I would really like to hear from people who have been through something similar:
Did anyone on chemo + immunotherapy have a persistent fever around 37.5–38°C for several days while otherwise feeling relatively well?
Was it eventually attributed to immunotherapy, chemotherapy, an infection, or tumor fever? How long did it last, and what tests helped your doctors figure out the cause?
Any personal experiences would be greatly appreciated.