Treatment for hep B linked to increased rates of colorectal and cervical cancer

[Nmarius]

Well, in few days i am supposed to start treatment with ETV 0.5mg. I was reading this article, what opinions do you have?



http://www.eurekalert.org/pub_releases/2016-04/eaft-tfc040816.php

// Researchers recommend regular screening for patients who have received long-term oral nucleos(t)ide analogue treatment for hepatitis B.
April 15, 2016, Barcelona, Spain: A new study presented today demonstrates a potential link between treatment of long-term oral nucleos(t)ide analogues and an increased risk of colorectal (p=0.029) and cervical (p=0.049) cancer in patients with chronic Hepatitis B virus (HBV). The study results were presented at The International Liver CongressTM 2016 in Barcelona, Spain.

Chronic HBV infection remains a global public health issue and continued prevention and control strategies are needed.1 Prolonged treatment with nucleos(t)ide analogues, which are used to prevent the virus from reproducing, are recommended for selected chronic HBV patients.2,3 However, questions have been raised regarding the long-term safety of such treatments.4

"Although our analysis showed that nucleos(t)ide analogue treatment does not increase overall incidence of liver, lung, breast and urinary/renal malignancies, it did reveal that patients with Hepatitis B virus on this treatment had a higher risk of developing colorectal and cervical cancers," said Professor Grace Wong, Department of Medicine & Therapeutics Academic at the Chinese University of Hong Kong and lead study author. "In light of these findings we strongly urge regular screening of these cancers to help prevent them from developing in patients taking nucleos(t)ide analogue treatment."

For their research, the authors of the Chinese study selected 45,299 patients who had been diagnosed with chronic HBV. Of these, 7,323 (16.16%) had undergone nucleos(t)ide analogue treatment. The primary outcome of the study was incident malignancies excluding hepatocellular carcinoma (HCC), the most common type of primary liver cancer.5 Follow-up duration was up to seven years, during this period the relative risk of primary outcome in patients with or without nucleos(t)ide analogue treatment was measured.

At the median follow-up of 4.4 years, malignancies occurred in 538 (2.1%) of untreated patients and 274 (5.7%) of those who had received nucleos(t)ide analogue therapy. Nucleos(t)ide analogue-treated patients had higher risks of developing colorectal cancer (adjusted Hazard Ratio (aHR) 2.17, 95% Confidence Interval (Cl) 1.08-4.36, p=0.029) and cervical cancer (aHR 4.41, 95% Cl 1.01-19.34, p=0.049). However, across treated and non-treated groups nucleos(t)ide analogue-treated patients had similar risks of developing other malignancies, including lung and pleural cancers, breast cancer and renal conditions.

"This large-scale study determines an important link between nucleos(t)ide analogue treatment and cervical and colorectal cancer," said Professor Tom Hemming Karlsen, EASL Vice-Secretary. "The results are important and could change cancer surveillance and management of patients treated for Hepatitis B."
//

[Aduiski]

"would like to see percentages on tdf only, etv only and lam only..."

Thats what I would love to see too...

etv should have the biggest research data on cancer (i guess any cancer detected on etv is registered) but until now they said nothing, so i guess data like the one on this study is not confirmed by bigger studies."

Good point. The reason they don't disclose it is probably because it would not be a very good news for them, and they are afraid they might be loosing their market share...
The question is whether Tenofovir data would be superior in that sense. Any studies done on Tenofovir? There must be some, at least on HIV patients...I'll have to search on it...

[Aduiski]

Table 1 contains data from which proportions can be inferred:

Lamivudine: 1681 people
ETV: 1051
ADV: 100
Telbivudine: 45
TDF: 10

So mostly Lamivudine and ETV...

[stef2011]

i would like to see percentages on tdf only, etv only and lam only...

etv should have the biggest research data on cancer (i guess any cancer detected on etv is registered) but until now they said nothing, so i guess data like the one on this study is not confirmed by bigger studies.

[stef2011]

i had a quick look, i didn t see percentages per nuc, my guess is that tdf is the safest one in this regard

[Aduiski]

They say that they used a 3-year landmark analysis, which in my understanding means that they excluded those patients that developed cancers within first 3 years of starting the observation/treatment.

Large majority of patients in this study were on Lamivudine and Entecavir
Source: https://www.researchgate.net/publication/276359092_Long-term_safety_of_oral_nucleostide_analogs_for_patients_with_chronic_hepatitis_B_A_cohort_study_of_53500_subjects

[Aduiski]

Based on their study one could conclude that it is the same whether one takes NUCs or not, at least with regards to malignancies/cancers, because according to their study people on NUCs have slightly lower the incidence of HCC but slightly higher the incidence of other (colorectal and cervical) cancers...in the end having the same rate of cancers...according to their study.

[stef2011]

optimizing vit d levels is known to cut all cancer to 70% on a big study, i ll have to look for it and other study reported a 50% less on hcc...in the end percentages like 2 and 5% dont look so relevant to me

[stef2011]

it looks like BS, cancer takes more than 4 years to become detectable, they had it already plus 2.1% to 5.7% dont look like meaningful statistical difference infact they say However, across treated and non-treated groups nucleos(t)ide analogue-treated patients had similar risks of developing......
what is the risk of general population by the way?

and what is the difference per nuc, we know etv is monitored for cancer risk