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Effectiveness of Photodynamic Therapy in Elimination of HPV in Mexican Women [pdf] (twin.sci-hub.tw)
238 points by new_guy 12 days ago | hide | past | web | favorite | 48 comments





Has anyone read the study? Severe side effects in almost every patient, and a 50% cure rate of CIN. Existing treatments for CIN have side effects in about 1% of patients and with a 90% cure rate:

https://my.clevelandclinic.org/health/diseases/15678-cervica...

Moreover, as the above makes clear, curing HPV is not necessary (especially with such an invasive technique) - only 1% of low grade CIN (which itself is a subset of all HPV) progress to cervical cancer.


Thank you for readying the actual study. News outlets are political and have their narratives. If there is no hard boiled source, it impossible to tell from one source what the actual facts are. Almost no one will compare different sources to filter the truth, most just stick with the outlets they used to.

> Moreover, as the above makes clear, curing HPV is not necessary

There's a body of evidence that HPV might be a factor of Alzheimer's and other neurodegenerative conditions. If that turns out to be true, curing HPV will be very much necessary.

https://www.cell.com/neuron/fulltext/S0896-6273(18)30421-5


That article doesn't reference HPV.

My bad. HHV != HPV. I have been misreading the OP article.

I'd delete the above if it was within time limit.


Amazing results using a proven therapy, wretched article. Here’s the actual study: https://twin.sci-hub.tw/6319/73863883d6bd8895505fcc8581dfc0e...

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?

> wretched article.

Indeed. This doesn't make any sense:

> she was able to eradicate HPV in [...] 57.2% in women who had lesions but don't have HPV.


OK, in that case we've updated the link from https://www.eluniversal.com.mx/english/mexican-scientist-cur.... If someone can suggest a better article we could use that.


No control group. Very small treatment group. Low power study. Possibly of interest to researchers for discussion, no value to clinician or general public.

Nice that they reported side effects of treatment including pain.


> The results of her investigation show that she was able to eradicate HPV in … 57.2% in women who had lesions but don't have HPV.

How do you eradicate HPV in a population that does not have HPV?


Presumably they eradicated the lesions, which were potentially precancerous.

With a mere snap of the fingers!

This sounds like nonsense. Unlikely and highly improbable. I sincerely hope im wrong...

This is good to see. I don't usually see a lot in the press about Mexico accept for the cartel-related news. Hard to believe I forget that Mexico is more or less a normal country, not some dystopian war zone.

Maybe you should head over there to see for yourself what it's like.

This summer, I'll be heading to Mexico (Monterrey) and San Antonio again, and I'm looking forward to Monterrey a lot more than San Antonio.

Mexico, apart from certain regions (like almost everywhere) is pretty great.


I agree with the sentiment but the "(like almost everywhere)" part frustrates me.

Where are the armed guards at gas stations in Canada? Where are the mass graves in Sweden? Where's the bribery-is-business-as-usual in England?

Don't pretend like everywhere has these kinds of problems. It really undercuts the valid point you have that there's a lot of great places in Mexico and it's generally populated by good people.


I meant you can find issues in all countries.

I live in a pretty safe country (Belgium), but there are parts of Brussels I would not like to walk at night.

It does not have to be as extreme as mass graves. But murders, robery, drugs, and other crimes occur in the countries you named as well.

(That said, I do consider them safe countries)


Canada and Sweden are really really far from the median for the planet. They are not representative at all. Try again with Malaysia, Indonesia, Nigeria, China, Bangladesh, Colombia, Brazil, Greece, Ukraine, etc.

how is op saying "almost anywhere" has the same issues? canada and sweden have issues too. talk to many aboriginals?

The countries of the American continents have a ton of historical baggage with regards to treatment of first nations / indigenous / aboriginal / native american people and plenty of current baggage. And I don't doubt Sweden does too. However, the current status is not in remotely the same league as the violence, corruption, and warfare raging throughout Mexico. This is quantifiably worse.

i didnt say anything about mexico. im replying to someone who says there arent parts of canada or sweden comparable to mexico. well this is ignorant. look up missing and murdered aboriginal women. does that count as violence to you? because aboriginal women make up like 1% of the canadian population, but something like 25% of murdered women. of course in broad strokes canada and mexico are very different (canada is wealthy, has no cartel, etc) but that doesnt mean there arent little bits of bad there and doesnt mean there arent bits of good in mexico (remember this reply traces to a parent comment praising a notewrothy academic study coming out of a country generally only mentioned in mainstream news for its problems). thats all.

Taking a step back, I'll try to explain where I'm coming from.

My read of Waterluvian's comment is that:

1. "Problems" (e.g., violence) quantifiably differ in magnitude between Mexico and other places. And,

2. Those differences matter. That is, the dismissal in the form of "well, everywhere has problems" is disingenuous.

To illustrate that, he provided three specific salient examples (armed guards at gas stations, mass graves, and rampant corruption).

My read of your response to that comment was that you dismissed the idea that armed guards, mass graces, and rampant corruption are a level beyond the violence in e.g., Canada and Sweden, because "what about aboriginals?" By dismissing Waterluvian's comment, you made a statement normalizing Mexico's level of violence.

So I tried to clarify that the difference in level of violence matters, and, here we are.

> i didnt say anything about mexico.

Sure you did. Denying "A != B" says something about A.

> im replying to someone who says there arent parts of canada or sweden comparable to mexico.

That's not what the comment you responded to said. Violence and corruption is quantifiably endemic to Mexico. Small populations in Canada and Sweden see outsized violence, but on the whole, those countries experience less violence.

To put some real numbers on it, there were 611 homicides in Canada in 2016, across a population of 36.26 million. That's 1.68 per 100,000 people. The homicide rate in Canada peaked at 3.03 per 100,000 in 1975.

In contrast, the homicide rate in the US peaked at 10.1 per 100k in 1974 and now hovers around 4.5 per 100k.

Mexico's homicide rate in 2016 was 19.3 per 100k. And "as of 2014, Mexico has the 16th highest rate of homicides committed against women in the world."[0]

If you're trying to illustrate that Canada is just as violent as Mexico, you picked a poor example.

[0]: http://www2.ohchr.org/english/bodies/cedaw/docs/ngos/CDDandC...


no, no, i am not making such a strong claim -- i absolutely agree in the differences you cited b/w canada and mexico. although im hesitant to generalize so much about a region; taken to the extreme, your argument is something like, "mexico is bad, canada is good" -- if instead youre only saying mexico is more violent in terms of per capita homicide, well that is trivially true so not subject to debate.

what im trying to get at is that we discuss the violence (valid a concern as it is) to the detriment of appreciating the rest -- that, generally, most mexican citizens are fairly typical cf. a canadian or swede in terms of their own morals and desires of life, but when we see an advancement such as the subject of this thread it is approached with an intrinsic skepticism.

does that make some kinda sense? its hard to say more on a mobile device :p


Yeah, that makes sense; I think we're more or less on the same page now. (Less: I am not making the claim that Mexico is bad, Canada is good, or that ordinary Mexicans are all that different from ordinary Canadians. Or that science journalism from Mexico should be approached with any more skepticism than science journalism from the rest of the world.)

> if instead youre only saying mexico is more violent in terms of per capita homicide, well that is trivially true so not subject to debate.

Yes, that's exactly what I'm saying :-). Per capita homicide, corruption, arming of the regular police; on all of these metrics Mexico stands out compared to affluent NATO countries. I thought that was kind of what this comment thread was debating; I misunderstood. Mea culpa. It can be hard to communicate clearly on the internet, especially on mobile. I appreciate you taking the time to help me understand your thoughts.


likewise, thanks!

Regio here. Hope you have some great carne asada with Carta Blancas.

If I may ask, what brings you here?


I’d say this article and your reaction says more about the nature of the news media as a whole than it does about you or Mexico.

A good reminder that the news is a terrible way to learn about the world.

Depends on what you want to learn. If you want a full scope of the risks plauging a certain region, the news can be pretty good. The issue is when you view incidents in the news disproportionally to their true rate of occurrence.

However, with incidents like cartel kidnapping and murdering 40+ students, including flaying them alive, and almost half of the individuals arrested in connection to the crime are police[0], it's not exactly the kind of incident where any rate of occurrence besides 0 is acceptable. I'd rather know that things like this happen in a specific region than not know. Anything else is reckless ignorance.

0. https://www.independent.co.uk/news/world/americas/cartel-mem...


Reminds me of when people think of the United States based on how the autonomous Chicago police force deals with violence in South Side Chicago

Foreigners routinely comment on the low level of training and discipline exhibited by the US police force.

Any and all accurate data is good data for assessing the risk of a region.

Only a small part adjacent to god-blessed America is something like a warzone.

The 91 people killed in January while stealing gasoline from a deliberately ruptured pipeline burned to death 320 miles South of the US border. When 43 students were rounded up by the police and handed over to a cartel for execution and disposal in 2014 they were 532 miles south of the US; halfway to Guatemala. The 2011 Monterrey casino arson attack that killed 52 people was 90 miles from the US.

I know it's the fashion to Blame America First in all things, but Mexico has enormous problems well beyond its border with the US.


The drug violence is fueled by the USA's demand for drugs. We also lack the political will to try things that have worked elsewhere, like decriminalization, even on a small scale.

Not saying the USA is responsible for solving Mexico's problems, but we do have a lot of national soul-searching to do if we want to get serious about drug violence in both countries.


> The drug violence is fueled by the USA's demand for drugs.

So goes the conventional group think. Thing is Mexico isn't the only nation that shares a long border with the US. Yet somehow Canada isn't yet another murder capital of the world, busily feeding the relentless US appetite for drugs.

But analyzing the difference between Mexico and Canada isn't something you're allow to do; it rapidly produces extremely uncomfortable results that contemporary good-thinkers don't ever dare entertain.


Nitpicking (sorry), but decriminialization of use doesn't fix the supply side of the equation — production, distribution, and sale would still be black market. To erode the cartels' profits we would also have to legalize (or decriminialize, but at that point, might as well just legalize) production and sale.

The drug violence is fueled by the USA's intelligence agencies being on slash supporting both sides.

Killed while stealing gasoline? they were filling running old trucks with gasoline and drilling on gasoline pipes.

> I know it’s the fashion to...

But thats not what they said. They said a small area within Mexico is like a warzone.

And then you wrote about several small areas, of which you highlighted incidents over the last decade, so I guess nothing is even happening in those areas now?

Interesting way to agree with someone. Handful of knowledge, weird flex but ok.


The original comment claimed that the small violent area of Mexico was (exclusively) adjacent to the US border.

The thrust of the comment you replied to was that in fact, violence was not constrained to the US border.

I think you failed to read tamalesfan's comment accurately (much less charitably). The snarky comment looks especially foolish when you're so off-base.


Okay, I was thinking they were referring to the country adjacent to the US border, and small parts of it

Different way of reading it


Michoacán is "adjacent" to America? It's one of the most dangerous places. Acapulco was recently Mexico's murder capital -- also nowhere near the US. Violence in Tamaulipas has declined quite a bit; certain interior states are far more dangerous these days. Mexico is a nice place, but the murder rate is 25 per 100,000 people, compared to 4.9 in the US and 6.2 globally.

As far as the war zone aspect -- I lived near Guadalajara in a small town called Chapala and, when you're in Guadalajara, it often does seem like a war zone. In our "peaceful" enclave, there were frequent (several times per year) shootouts with police and gang-on-gang violence along with innocent people being victimized, robbed or killed. Just a few days ago, a 78 year old Canadian expat was walking through San Antonio Tlayacapan (a nice community next to lake Chapala) and was shot in the head twice in broad daylight on the street.[0] Chapala is pretty much a peaceful retirement community, yet even there, there is brutal violence.

With the Jalisco NG Cartel, there is a substantial military and paramilitary presence across various areas of Guadalajara. Large police pickup trucks with machine guns mounted in the bed isn't something I've ever seen -- outside of an actual war zone. I've been in US Army units that have been less heavily armed than some of the standard police in Guadalajara. Heavily armed patrols in full military "battle-rattle" are a mainstay of the city. Anyone that's suggesting that Mexico is a peaceful place must be asleep. The Mexican people are generally very peaceful and I typically feel safe enough there, but that's not much different than how friendly Afghanis are -- despite Taliban activity in the neighborhood. You're definitely taking much different precautions traveling through Mexico than you would traveling through Los Angeles.

I love Mexico, my wife is from there, I go there all the time -- but suggesting it's a war zone? That's not too far from the truth -- the Mexican marines recently took over security in Acapulco.[4] If that isn't the definition of "war zone," I'm not sure that word has any meaning. You'd have to be oblivious not to see the war zone aspects in many parts of the country.

[1] https://mexiconewsdaily.com/news/canadian-expat-78-shot-and-... [2] https://www.thesun.co.uk/news/6024568/cancun-murders-mexico-... [3] https://mexiconewsdaily.com/news/michoacan-turf-war-fuels-cr... [4] https://www.telegraph.co.uk/news/2018/09/26/marines-swoop-ac...


FWIW, I've seen a police technical with machine gun in Los Cabos, of all places (almost no cartel activity), so I suspect they may correlate more closely to police morale than to operational necessity.



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