Abstract: This study aimed to determine the effectiveness of photodynamic therapy (PDT), using δ‐aminolevulinic acid (5‐ALA), in the elimination of premalignant cervical lesions in Mexican patients with human papillomavirus (HPV) infection and/or cervical intraepithelial neoplasia (CIN). Thirty women diagnosed with CIN I and/or positive for HPV participated in the study. Topical 6% 5‐ALA in gel form was applied to the uterine cervix; after 4 h, the lesion area was irradiated with a light dose of 200 J cm−2 at 635 nm. This procedure was performed three times at 48‐h intervals. Clinical follow‐up was performed at 3, 6, and 12 months after the initial PDT administration, by colposcopy, cervical cytology, histopathological analysis, polymerase chain reaction, and hybrid capture. Of HPV‐infected patients without evidence of CIN I, 80% cleared the infection, while HPV associated with CIN I was eliminated in 83% of patients (P < 0.05). At 12 months, CIN I had regressed in 57% of patients, although this response was not statistically significant. PDT using 6% 5‐ALA is concluded to be effective in eliminating HPV infection associated or not with CIN I.
This is an awkward study poorly described in the journal paper. They are studying two groups, one that is CIN+ and HPV+ and the other that is CIN- but HPV+. They are applying the same treatment. It's essentially two studies. They provide no treatment control groups but seem to rely on control statistics from a previous, similar study, and only mention it in passing in the discussion. The control that should be covered is for CIN that naturally regresses, which is clearly a significant case as they exclude women under 25 because they "easily regress." They note that their final regression rate with treatment is the same as previously reported natural regression after two years (57% vs. 58%), but indicate their rate of regression to that point is faster (6 vs. 24 months), but not statistically significantly so - they only had 12 CIN+ HPV+ subjects. They also seem to rely on, but make no mention of, natural HPV viral clearance by the immune system. They similarly indicate that the treatment group's clearance rate of HPV is similar to previously reported, but un-cited, rates of natural clearance, but with a sharper slope to the clearance rate among the treated patients. They offer that this might be due to coincidentally specific immune response to the treatment that corresponds to the necessary immune response for effective natural HPV clearance.
In many respects, this is a report of negative results, and they don't really hide that. They just wait until the discussion to explicitly mention any of the key information. But respect for publishing negative results.
EDIT: changed "article" to "journal paper" to avoid confusing the published research paper with the news report of it that was originally linked and which I didn't bother wasting time reading.
> Of HPV‐infected patients without evidence of CIN I, 80% cleared the infection,
Over 50 percent of new HPV infections are cleared in 6 to 18 months, and 80 to 90 percent will have resolved within two to five years.
> while HPV associated with CIN I was eliminated in 83% of patients (P < 0.05). At 12 months, CIN I had regressed in 57% of patients, although this response was not statistically significant.
CIN 1 lesions will regress in most women. As an example, a retrospective study of 680 women with biopsy-proven CIN 1 found the following cytology and/or histology results: (1) at six months, 49 percent regressed to negative, 35 percent had persistent CIN 1, and 7 percent had high-grade lesions; (2) at 12 months, among the patients with negative results at six months: 80 percent were negative, 17 percent had low-grade lesions, and 4 percent had high-grade lesions; and (3) at 12 months, among patients with persistent CIN 1 at six months: 50 percent were negative, 46 percent had low-grade lesions, and 4 percent had high-grade lesions (Bansal 2008.)
> PDT using 6% 5‐ALA is concluded to be effective in eliminating HPV infection associated or not with CIN I.
Doesn’t seem to be much better than the natural course of the untreated disease.
Disappointingly, there is no mention in the paper of how the Hypothesis testing is performed, including no mention of randomized control group. Are these details described elsewhere? Are they assuming a null Hypothesis of no remission with no control group?
Abstract: This study aimed to determine the effectiveness of photodynamic therapy (PDT), using δ‐aminolevulinic acid (5‐ALA), in the elimination of premalignant cervical lesions in Mexican patients with human papillomavirus (HPV) infection and/or cervical intraepithelial neoplasia (CIN). Thirty women diagnosed with CIN I and/or positive for HPV participated in the study. Topical 6% 5‐ALA in gel form was applied to the uterine cervix; after 4 h, the lesion area was irradiated with a light dose of 200 J cm−2 at 635 nm. This procedure was performed three times at 48‐h intervals. Clinical follow‐up was performed at 3, 6, and 12 months after the initial PDT administration, by colposcopy, cervical cytology, histopathological analysis, polymerase chain reaction, and hybrid capture. Of HPV‐infected patients without evidence of CIN I, 80% cleared the infection, while HPV associated with CIN I was eliminated in 83% of patients (P < 0.05). At 12 months, CIN I had regressed in 57% of patients, although this response was not statistically significant. PDT using 6% 5‐ALA is concluded to be effective in eliminating HPV infection associated or not with CIN I.