Photodynamic therapy with systemic meta-tetrahydroxyphenylchlorin in the treatment of anal intraepithelial neoplasia, grade 3.
OBJECTIVE
Anal cancer and preneoplastic anal lesions (anal intraepithelial neoplasia, AIN) rising especially in men having sex with men (MSM). There are no widely accepted treatment standards for AIN. Photodynamic therapy (PDT) using the systemic sensitizer meta-tetrahydroxyphenylchlorin (mTHPC) has the potential to treat the anal area even when the exact borders of the preneoplastic anal lesion cannot easily be visualized.


METHODS
In this prospective intervention study, 15 HIV-positive MSM with AIN 3 were treated in 25 PDT-sessions using mTHPC intravenously administered at drug doses of 0.075-0.15 mg ml(-1) and illumination at 48  hours. The illumination was performed using a custom made applicator using either red light (652 nm) to a measured intended fluence of 10 and 20 J cm(-2) and green light (532 nm) to a measured intended fluence of 105, 210, and 340 J cm(-2) . Red and green illuminations were performed at a (green) equivalent fluence rate of 105 mW cm(-2) .


RESULTS
Initial complete response was seen in 7/25 (28%) of treatments and another 4/25 (16%) initial partial responses. After an average 8 months, recurrences were detected in 7/11 (64%) of sessions that initially showed response. A total 4/25 (16%) showed persistent complete response 6-15 months after green light illumination. Red light illuminations caused more significant side effects combined with no persistent complete response. Reported side effects were intense pain, bloody and purulent rectal discharge, and anal stricture formation, in one patient.


CONCLUSIONS
The results show that the use of systemic mTHPC is partially effective for the treatment of AIN 3.
Department of Dermatology, Erasmus MC, Rotterdam, The Netherlands. e.vandersnoek@erasmusmc.nl
Eric M
EM
van der Snoek
Jan C
JC
den Hollander
Jan B
JB
Aans
Henricus J C M
HJ
Sterenborg
Marchina E
ME
van der Ende
Dominic J
DJ
Robinson
D000328:Adult; D001005:Anus Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002278:Carcinoma in Situ / Q000188:drug therapy* / Q000473:pathology; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008297:Male; D008652:Mesoporphyrins / Q000627:therapeutic use*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D010147:Pain Measurement; D010778:Photochemotherapy / Q000009:adverse effects / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011446:Prospective Studies
D008652:Mesoporphyrins; D017319:Photosensitizing Agents; C072269:temoporfin