Friday, November 18, 2016

Melanoma

    This weeks cancer topic is melanoma skin cancer. Melanoma is a cancer that begins in the skin cells. Melanoma begins specifically in the melanocyte type of skin cells. Melanocytes make a brown pigment known as melanin, which is what gives skin the brown or tan color. When you lay out to tan and are exposed to more sunlight the melanocytes will make more of the pigment. Melanomas can occur anywhere on your skin, but primarily occur on the chest or back in men and the legs of women. This type of skin cancer can come from moles that turn into melanoma. UV rays from sunlight or from tanning beds are a major cause of melanoma. These UV rays damage the DNA in the skin, which can alter how genes control how skin cells grow and divide. DNA changes can turn on oncogenes, which help cells grow and divide, or turn off tumor suppressor genes, which keep cell growth in check or cause cells to die.

    Current research suggests that increased sun exposure as a child and teenager is linked to development of melanoma. Majority of those with melanoma have reported having sunburns or other intense sun exposures as a child. Researcher have also noted that their has been an increase in melanomas occurring on the arms, neck, and face. These areas are commonly exposed, especially in men, which could lead to a higher risk of melanoma. Researchers are studying whether or not these different types of exposures to UV (including tanning booths) creates changes in different genes. If this is the case, different treatments may be needed for different exposure histories.

    While it is scary to think that our exposure to sun as a child and teenager could be the reason for developing melanoma later in life, we should still take precautions to avoid getting skin cancer. The best thing you can do is wear sunscreen, limit your exposure to UV rays, and know your body. If you notice any strange discoloration, growths, bumps, patches, or sores that won't go away.

Reference:
http://www.cancer.org/cancer/skincancer-melanoma/

Wednesday, November 9, 2016

Hodgkin Lymphoma

      Hodgkin's lymphoma is a type of lymphoma, which is a group of blood cell tumors that develop from lymphocytes. Generally one will experience fevers, night sweats, and weight loss. A proportion of Hodgkin's tumors contain the Epstein-Barr virus (EBV), which suggests that this virus is a contributing factor to the develop of the cancer. EBV, or human herpesvirus 4, is one of the known viruses in the herpes family. The virus infects the B cells of the immune system and epithelial cells, and once the infection is under control EBV latency will persist for the rest of the individual's life.

     But how does this virus lead to Hodgkin's lymphoma? The mechanism by which EBV might cause Hodgkin's lymphoma is not well understood. However, almost 40% of individuals who have Hodgkin's lymphoma are also infected with EBV. EBV possibly triggers the pathogenic mechanism of Hodgkin's disease, which means that EBV could play a direct or indirect role in he pathogenesis. According to Flavell, cloned viral probes and Southern blot methods were used to detect EBV DNA in 20-25% of Hodgkin's disease tumor specimens. This approach, however, could not determine the locality of the EBV genome in the tissues. This method of detecting EBV DNA was the first to demonstrate its existence in Hodgkin-Reed Sternberg (HRS) cells. HRS cells are different large cells found in individuals with Hodgkin's lymphoma.

    Those that are diagnosed with Hodgkin's lymphoma will generally undergo radiation therapy or chemotherapy. Sometimes both treatments are used, but this depends on how far the disease has progressed in the individual. Luckily, there is a high cure rate and long survival for patients battling this disease.

Link to the paper used:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1186979/

Friday, November 4, 2016

HPV in Men

     Continuing off of my previous blog, this week I will be discussing human papillomavirus (HPV) and its role in males. In case you missed my previous blog, HPV is a common infection to those who are sexually active. However, most infections will go away on their own without any further problems. Getting the HPV vaccine can help prevent the onset of cervical cancer or genital warts that may occur from HPV. This vaccine is very common for teenage girls to receive, but should males be receiving this vaccine too?

     The answer is yes, but there are some considerations. According to the CDC, it is recommended that boys between the ages of 11 and 12 receive the vaccine, but boys as young as 9 and through the age of 21 can receive the vaccine. While HPV isn't cancer, it causes certain changes in the body that can lead to cancer. While cervical cancer is what we hear about most, there are cancers that can occur in males from this infection. Males can develop penile cancer if the infection doesn't go away. Both men and women can develop anal cancer and even cancer in the back of the throat, known as oropharyngeal cancer. Good news, however, is that HPV-related cancers are not very common in men even though HPV is one of the most commonly transmitted infections. Not so good news is that there are currently no approved tests for HPV in men and there are also no specific treatments for HPV. There are only treatments for the symptoms, such as genital warts.

     Most of the cancers caused by HPV can be prevented with the HPV vaccination. Approximately 63% of penile cancers are linked to HPV, along with 91% for anal cancers, and 72% for cancer of the back of the throat. So how can HPV lead to cancer? HPV is a DNA virus that contains genes which encode for biological processes that allow the virus to in the cell nucleus of its' host cell. The virus will replicate in the nucleus until cell death. At this point, the virus will then be allowed to infect other epithelial cells and eventually obtain the ability to embed itself into the DNA of the host. This gives the virus the ability to control cellular mechanisms and will mess up cell regulation. This deregulation will cause uncontrolled cell growth, which in turn causes the cancers that have been discussed. While not all HPV types have this ability, as discussed in my previous blog, there are certain cancer-causing types that could occur.

For more information from my readings here are the links:
http://www.cdc.gov/std/hpv/stdfact-hpv-and-men.htm
http://www.canceradvocacy.ca/reportcard/2012/Report%20Card%20on%20Cancer%20in%20Canada%202011-12.pdf#page=6 (page 6 "HPV in Men")