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Laser therapy of cervical intraepithelial neoplasia
CORRESPONDENCE
Laser therapy of cervical intraepithelial neoplasia To the Editors:
In the article by Baggish, entitled "High-powerdensity carbon dioxide laser therapy for early cervical neoplasia," which appeared in the January 1, 1980, edition of the GRAy rOURNAL, on oa~re 117' Dr. Ba~r~rish claims a high cure ~ate with high-power-density~ar bon dioxide laser therapy for cervical intraepithelial neoplasia (CIN). The primary failure rate with laser in Dr. Baggish's hands is 26% and it is 32% for CIN III. For cryosurgery, the primary faiiure rate is around 10%. 1 The failure rate after second therapy, in Dr. Baggish's hands, was approximately 7%, which is no better than that with cryosurgery. Baggish criticizes cryosurgery because it supposedly has major hazards and moves the squamocolumnar junction into the canal. Where are his data? When compared to conization, which has a failure rate of less than 4%, according to an article by Kolstad which Dr. Baggish cited, laser rates very poorly. The results obtained by Carter and Stafl and their associates, who used low-power density, both of whom he cited, had a lower primary failure rate than that of Dr. Baggish. Their overall cure rate was lower than his, after two treatment sessions. The treatment of diethylstilbestrol (DES)-related epithelial changes is totally unnecessary and represents meddlesome medicine. The 15 cases of carcinoma in situ in DES-exposed offspring in his 120 patients is three times as many as we have in the 4,000 DES-exposed offspring in the nationwide National Cooperative Diethylstilbestrol Adenosis Project. Perhaps not all of his patients had a legitimate carcinoma in situ. The use of electrodiathermy by Chanen and Hollyock,2 which requires general anesthesia, has a superb cure rate with very few complications. I know of no single death in Australia, and they have treated more than 2,000 patients in Sidney and Melbourne. The recommendations for caution must be strongly emphasized since more carefully controlled studies must be carried out with the laser before it can be considered a legitimate treatment modality. Duane E. Townsend, M.D. Division of Gynecologic Oncology Department of Obstetrics and Gynecology Cedars-Sinai Medical Center Los Angeles, California 90048
838
REFERENCES I. Townsend, D. E., and Ostergard, D. R.,: Cryocauterization
for preinvasive cervical neoplasia, J Reprod. Med. 6:171,
1971. 2. Chanen, \A/., and HoUyock, V. E.: Colposcopy and the con-
servative management of cervical dysplasia and carcinoma in situ, Obstet. Gynecol. 43:527, 1974.
Repiy to Dr. iownsend To the Editors:
Dr. Townsend's letter unfortunately extracts data from my article, "High-power-density carbon dioxide laser therapy for early cervical neoplasia," out of context. He quite surely knows that all cases treated by laser were included in these statistics, i.e., even patients with early CIN who were treated to a shallow depth by laser beam prior to the current routine removal of the entire squamocolumnar junction down to 5 mm. Retreatment was done at 3 weeks and again at 6 weeks. Since the first 50 patients were examined every other day and since early follow-up therapy was very aggressive, many of these "retreatments" were most probabiy carried out for atypical metaplasia, a finding prevalent in the healing phase. Primary therapy in this study was considered to terminate after 6 weeks, i.e., after 6 weeks patients were examined every 6 months. In actuality this compares favorably with cryosurgery standards where in fact every patient initially receives two treatments. Complete healing had occurred in the cases requiring two additional laser exposures before the cervical discharge had stopped in a like group of cryosurgery-treated patients. These criteria are in fact no different from those suggested in an article which Townsend coauthored: 'Two cryosurgical treatments nrerc used in most patients before it \Vas considered a failure." 1 The long-term cure rate in my series was 95%, i.e., there were five failures in 11.5 cases. Dr. Townsend cites a cryosurgical failure rate of 10% but supplies no follow-up data. AF;ain in the article he coautho-red one year later, the overall residual failure rate was 19% in the entire group of 118 cases and 33% in the CIN III group. The latter cryosurgical failure statistics are corroborated in several other published series. Creasman and associates 2 reported persistent CIN following cryotherapy in 22 of 75 patients (30%). When a single treatment was given, the failure rate was 48% as compared to 18.7% when two treatments were performed. Gray and Christopherson'l routinely
Laser therapy of cervical intraepithelial neoplasia To the Editors:
In the article by Baggish, entitled "High-powerdensity carbon dioxide laser therapy for early cervical neoplasia," which appeared in the January 1, 1980, edition of the GRAy rOURNAL, on oa~re 117' Dr. Ba~r~rish claims a high cure ~ate with high-power-density~ar bon dioxide laser therapy for cervical intraepithelial neoplasia (CIN). The primary failure rate with laser in Dr. Baggish's hands is 26% and it is 32% for CIN III. For cryosurgery, the primary faiiure rate is around 10%. 1 The failure rate after second therapy, in Dr. Baggish's hands, was approximately 7%, which is no better than that with cryosurgery. Baggish criticizes cryosurgery because it supposedly has major hazards and moves the squamocolumnar junction into the canal. Where are his data? When compared to conization, which has a failure rate of less than 4%, according to an article by Kolstad which Dr. Baggish cited, laser rates very poorly. The results obtained by Carter and Stafl and their associates, who used low-power density, both of whom he cited, had a lower primary failure rate than that of Dr. Baggish. Their overall cure rate was lower than his, after two treatment sessions. The treatment of diethylstilbestrol (DES)-related epithelial changes is totally unnecessary and represents meddlesome medicine. The 15 cases of carcinoma in situ in DES-exposed offspring in his 120 patients is three times as many as we have in the 4,000 DES-exposed offspring in the nationwide National Cooperative Diethylstilbestrol Adenosis Project. Perhaps not all of his patients had a legitimate carcinoma in situ. The use of electrodiathermy by Chanen and Hollyock,2 which requires general anesthesia, has a superb cure rate with very few complications. I know of no single death in Australia, and they have treated more than 2,000 patients in Sidney and Melbourne. The recommendations for caution must be strongly emphasized since more carefully controlled studies must be carried out with the laser before it can be considered a legitimate treatment modality. Duane E. Townsend, M.D. Division of Gynecologic Oncology Department of Obstetrics and Gynecology Cedars-Sinai Medical Center Los Angeles, California 90048
838
REFERENCES I. Townsend, D. E., and Ostergard, D. R.,: Cryocauterization
for preinvasive cervical neoplasia, J Reprod. Med. 6:171,
1971. 2. Chanen, \A/., and HoUyock, V. E.: Colposcopy and the con-
servative management of cervical dysplasia and carcinoma in situ, Obstet. Gynecol. 43:527, 1974.
Repiy to Dr. iownsend To the Editors:
Dr. Townsend's letter unfortunately extracts data from my article, "High-power-density carbon dioxide laser therapy for early cervical neoplasia," out of context. He quite surely knows that all cases treated by laser were included in these statistics, i.e., even patients with early CIN who were treated to a shallow depth by laser beam prior to the current routine removal of the entire squamocolumnar junction down to 5 mm. Retreatment was done at 3 weeks and again at 6 weeks. Since the first 50 patients were examined every other day and since early follow-up therapy was very aggressive, many of these "retreatments" were most probabiy carried out for atypical metaplasia, a finding prevalent in the healing phase. Primary therapy in this study was considered to terminate after 6 weeks, i.e., after 6 weeks patients were examined every 6 months. In actuality this compares favorably with cryosurgery standards where in fact every patient initially receives two treatments. Complete healing had occurred in the cases requiring two additional laser exposures before the cervical discharge had stopped in a like group of cryosurgery-treated patients. These criteria are in fact no different from those suggested in an article which Townsend coauthored: 'Two cryosurgical treatments nrerc used in most patients before it \Vas considered a failure." 1 The long-term cure rate in my series was 95%, i.e., there were five failures in 11.5 cases. Dr. Townsend cites a cryosurgical failure rate of 10% but supplies no follow-up data. AF;ain in the article he coautho-red one year later, the overall residual failure rate was 19% in the entire group of 118 cases and 33% in the CIN III group. The latter cryosurgical failure statistics are corroborated in several other published series. Creasman and associates 2 reported persistent CIN following cryotherapy in 22 of 75 patients (30%). When a single treatment was given, the failure rate was 48% as compared to 18.7% when two treatments were performed. Gray and Christopherson'l routinely