Published online Jul 24, 2019. doi: 10.5306/wjco.v10.i7.247
Peer-review started: March 4, 2019
First decision: April 11, 2019
Revised: July 8, 2019
Accepted: July 16, 2019
Article in press: July 17, 2019
Published online: July 24, 2019
Checkpoint-Inhibition has revolutionized the treatment for several entities such as melanoma and renal cell carcinoma. The first encouraging experience in ovarian cancer was reported for nivolumab, a fully humanized anti-programmed death-1 antibody. Pseudoprogression is a new phenomenon associated with these novel immuno-oncologic agents. It can be explained by infiltrating leucocytes and edema that result in a temporary increase in tumor size and delayed subsequent shrinkage due to tumor cell destruction.
We report on a 47-year old patient with platinum-resistant ovarian cancer that was treated off-label with nivolumab 3mg/kg iv d1q14d. She first experienced classic pseudoprogression with inguinal lymph node swelling after cycle two and subsequent shrinkage. After 6 cycles she presented with rectal bleeding and progressive disease was diagnosed due to new tumor infiltration into the rectum.
Clinicians should be aware of pseudoprogression, its underlying mechanisms and strategies to discriminate pseudo- from real progression in ovarian cancer.
Core tip: Clinicians have to be aware of the phenomenon of pseudoprogression despite its rather rare occurrence. As both- pseudo-progression and real progression present with an increase in tumor size, the only certain way to differentiate between them is the occurrence of infiltrating growth. While the increase of tumor size in pseudoprogression can be explained by benign growth due to immune cell infiltration and edema, only malign growth of a real progression has the ability to infiltrate other tissues. When in doubt whether a pseudoprogression has occurred, we suggest cautious continuation of checkpoint-inhibition paired with corticoids to lower adverse effects if necessary.