I received an email from a colleague with a link to an online magazine piece about re: evidence on the dangers of smokeless tobacco (ST). When I read the brief article I felt the need to see the actual published study. This is because one of the things said in the ScienceDaily press release was that the tobacco was commonly used in other parts of the world. I had to ask myself, “What does this scientific finding mean to us – the USA?” I expected that I would find that the tobacco analyzed, which did cause some cellular changes that could lead to cancer, was NOT a product used in this country. That has happened before, both with good and bad outcomes, and it is important as a health educator that I know what I am talking about- yes?
I was able to access the journal article in Chemical Research in Toxicology.
Well of course I was blown away by the technical nature of the study and it was somewhat (ok very much so) over my head. Very basically an enzyme abbreviated as CYP and its protein subtypes will break down (in phases) the cancer causing agents in tobacco and other products. Often in tobacco we are referring to tobacco specific nitrosamines or TSNAs. In this instance the metabolism of the TSNAs or the breakdown of them by the enzymes can affect the cells in such a way as to change DNA. When DNA is changed, cells can mutate and become cancerous. This study showed that there are several organ systems affected by this toxic metabolism and thus smokeless tobacco could lead to several types of cancer. This is not a study to say that ST causes cancer, only that the processes that were seen are the same that in other situations have created a cancerous condition.
Still, the type of tobacco used in the region of study, Southeast Asia and India, is not the common tobacco used in the USA or even Western Europe. The researchers studied the effects of the tobacco metabolites from a certain blend called gutkha which according to Wikipedia and other sources is a mixture of tobacco and crushed betel nut, catechu, lime and other flavorings. What is catechu you might ask? It is some type of palm plant that grows in India and similar areas.
The ScienceDaily article did not at all note the type of tobacco or more exactly, tobacco juice (tobacco mixed with saliva), that was studied. This gutkha is not Copenhagen, Skoal or Redman and it is known to be worse than the Swedish brand of snus – so the article is good and as someone concerned with global health it is relevant, but as a US tobacco educator I would be wise to make the distinction of which tobacco causes which harm in my presentations as the one thing I want to be sure of is that I, unlike Big Tobacco, tell the truth!
Showing posts with label clinical studies. Show all posts
Showing posts with label clinical studies. Show all posts
Saturday, June 26, 2010
Monday, April 19, 2010
Tumor Analysis
This morning I read a brief news statement about a lung cancer clinical trial referred to as BATTLE that is underway at the M.D. Anderson Cancer Center in Texas. I have since contacted the reporter, reviewed the study website, read the study particulars on the US Institute of Health website for clinical trials, skimmed over several scholarly articles and then, read an article by another reporter which HAD the piece of information I needed in order to proceed with this post.
The study is a promising one which is addressing the treatment of the deadliest cancer - cancer of the lung. In the Anderson study, persons who have late or end stage non small cell lung cancer (nsclc) and who meet certain inclusion criteria - including having been through one course of first line treatment - (FDA approved medication for lung cancer treatment) - which did not slow or stop the progression of their cancer are entered into part one of the study, or the umbrella phase.
All of the persons have tumors ( small cell lung cancer, the most common one for smokers, tends to be diffuse) and these tumors are biopsied. Each tumor has characteristics and based on those characteristics, the volunteers are placed into one of four groups for part two of the study. This is a Phase II drug trial. They are put on a study medication for 8 weeks and then the tumor characteristics are reviewed again. A successful outcome is when the disease does not progress and people do not die. If progression has occurred, the person is taken out of the study and allowed to go on to receive standard treatment through their own provider.
I understand that tumors can have different fuels and expression - we often hear a distinction between estrogen receptor positive or negative breast cancer. That is what I was trying to find out with regard to this study.
So yes, lung cancer tumors can be fueled by different proteins, can be a result of expressions of certain genes, or be caused by a mutation on a certain gene. It is this distinction that the scientists make before putting the patient on one of the study drugs. Some success has been noted already with certain medications and tumor types. The study is not complete and full disclosure is pending.
I wonder if the tumor histories are used to tell what type of nsclc a person has. I also wonder if tobacco use is allowed during the study and if the patients were tobacco users. I did not see tobacco use as an exclusion for the study, but I did see this statement: Any condition that is unstable or could jeopardize the safety of the patient and its compliance in the study, in the investigator's judgment. I would consider smoking during treatment of lung cancer something that could jeopardize safety - wouldn't you?
This is a promising study - but to be clear, most persons with advanced stages of lung cancer do not live past a year. In the second article I read, it was noted that of the people in the study receiving this personalized approach to care, 38% survived to one year. I read that as 58% died. And nsclc is supposed to have a better survival rate that small cell lung cancer.
I would like to know if the type of nsclc was determined, as there are three - adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Do the proteins, mutations,or expressions determine that categorization or are their various biomarkers within disease type as well? Perhaps this will be answered when the study is published - if not - I will seek answers from a cancer organization.
Over 80% of lung cancer is caused by tobacco smoke - the most common nonsmoker lung cancer is the nsclc described here - however, even that type is most often caused by smoking.
The study is a promising one which is addressing the treatment of the deadliest cancer - cancer of the lung. In the Anderson study, persons who have late or end stage non small cell lung cancer (nsclc) and who meet certain inclusion criteria - including having been through one course of first line treatment - (FDA approved medication for lung cancer treatment) - which did not slow or stop the progression of their cancer are entered into part one of the study, or the umbrella phase.
All of the persons have tumors ( small cell lung cancer, the most common one for smokers, tends to be diffuse) and these tumors are biopsied. Each tumor has characteristics and based on those characteristics, the volunteers are placed into one of four groups for part two of the study. This is a Phase II drug trial. They are put on a study medication for 8 weeks and then the tumor characteristics are reviewed again. A successful outcome is when the disease does not progress and people do not die. If progression has occurred, the person is taken out of the study and allowed to go on to receive standard treatment through their own provider.
I understand that tumors can have different fuels and expression - we often hear a distinction between estrogen receptor positive or negative breast cancer. That is what I was trying to find out with regard to this study.
So yes, lung cancer tumors can be fueled by different proteins, can be a result of expressions of certain genes, or be caused by a mutation on a certain gene. It is this distinction that the scientists make before putting the patient on one of the study drugs. Some success has been noted already with certain medications and tumor types. The study is not complete and full disclosure is pending.
I wonder if the tumor histories are used to tell what type of nsclc a person has. I also wonder if tobacco use is allowed during the study and if the patients were tobacco users. I did not see tobacco use as an exclusion for the study, but I did see this statement: Any condition that is unstable or could jeopardize the safety of the patient and its compliance in the study, in the investigator's judgment. I would consider smoking during treatment of lung cancer something that could jeopardize safety - wouldn't you?
This is a promising study - but to be clear, most persons with advanced stages of lung cancer do not live past a year. In the second article I read, it was noted that of the people in the study receiving this personalized approach to care, 38% survived to one year. I read that as 58% died. And nsclc is supposed to have a better survival rate that small cell lung cancer.
I would like to know if the type of nsclc was determined, as there are three - adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Do the proteins, mutations,or expressions determine that categorization or are their various biomarkers within disease type as well? Perhaps this will be answered when the study is published - if not - I will seek answers from a cancer organization.
Over 80% of lung cancer is caused by tobacco smoke - the most common nonsmoker lung cancer is the nsclc described here - however, even that type is most often caused by smoking.
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