Prostate specific antigen change after administration of nimotuzumab in prostate cancer.

Dear Editor,

The new concept in management of metastatic cancer is using immunotherapy. A new drug, nimotuzumab, has been recently introduced for this purpose It is considered as a targeted therapy against cancer.[12] In brief, nimotuzumab is a humanized monoclonal antibody with a specific targeted binding site at the epidermal growth factor.[12] As an epidermal growth factor inhibitor, nimotuzumab leads to downregulation of EGFR phosphorylation leading to a decrease of tumorigenesis.[12] Here, the authors would like to share their experience on prostate specific antigen (PSA) change after administration of nimotuzumab in a patient with prostate cancer and colon cancer. The present case is a 55-year-old Thai male patient with Stage III colorectal cancer. This patient underwent sigmoidectomy, without any additional chemotherapy. The patient had high PSA (about 3 times the normal) indicating prostate cancer. Thus, this patient was diagnosed to have prostate cancer as well as synchronous colorectal cancer, both diagnosed at the same time. A prostate biopsy revealed no malignant tissue. The patient did not have any symptoms of prostate cancer and there was no objective evidence of other metastatic disease on imaging. The patient refused prostatectomy, hormonal therapy or chemotherapy and requested for alternative cancer therapy therefore he was referred for treatment with nimotuzumab (dosage 200 mg/week, intravenously) Since prostate cancer is known to express epidermal growth[3] factor that is the target of nimotuzumab, hence, the alternative treatment by this targeted therapy was selected.

Here, the authors specifically focused on the change of PSA in this patient ranging from pre- to post-treatment. A dramatic decrease of the PSA level could be seen in this case [Table 1]. This is the first reported case in the world showing the success of PSA suppression, for control of prostate cancer, by nimotuzumab. Nevertheless, further studies are needed to define the role of nimotuzumab in the therapy of prostate cancer.

Table 1

Change of PSA level in the patient