Oncogenic Virus-Driven Tumors: Types, Symptoms and Treatment

Introduction

The term oncogenic virus refers to viruses that cause cancer. Viruses are usually infectious, spreading the disease from one individual to another. Certain viruses not only cause infections but also cause cancers by various mechanisms. Tumors arising from cancer are specifically treated either by surgery or medical therapies.

What Are Oncogenic Viruses?

Oncogenic viruses (or oncoviruses) can cause cancer. They can affect humans and animals.

Following are the types of oncogenic viruses:

• Human papillomaviruses (HPV).

• Epstein-Barr virus (EBV).

• Hepatitis B virus (HBV).

• Human T lymphotropic virus 1 (HTLV1).

• Hepatitis C virus (HCV).

• Merkel cell polyoma virus (MCPyV).

• Kaposi sarcoma-associated herpes virus (KSHV), also known as human herpes virus 8 (HHV8).

What Is Human Papillomaviruses (HPV)?

Human papillomavirus (HPV) is an infection caused by a virus transmitted by skin-to-skin contact and is most commonly a sexually transmitted infection.

Clinical Findings of Human Papillomaviruses (HPV):

• Presence of genital warts.

• Causing cervical cancer.

• Head, neck, and throat cancer.

Treatment of Human Papillomaviruses (HPV):

• Genital warts are treated with medications, freezing with liquid nitrogen, or burning with current. However, removing warts is not a cure for the virus, and the recurrence of warts is the same.

• Cancers caused by human papillomaviruses (HPV) are treated based on the type by chemotherapy, surgery, or radiotherapy.

What Is Epstein-Barr Virus (EBV)?

Epstein-Barr virus (EBV) is also known as human herpes virus 4. It is the most common viral infection that spreads through contact with infected bodily fluids, like saliva.

Clinical Findings of Epstein-Barr Virus (EBV):

• Fever.

• Rash.

• Splenomegaly (increase in the size of the spleen).

• Fatigue.

• Swollen liver.

Treatment:

Until this day, there has been no clinical treatment for Epstein-Barr virus (EBV). However, the following precautions can be taken to relieve symptoms:

• Staying hydrated by drinking fluids.

• Taking proper rest.

• Medications for pain and fever.

What Is the Hepatitis B Virus (HBV)?

Hepatitis b virus (HBV) is a life-threatening viral infection spreading globally. It mostly spreads from parent to off-spring at birth and is also due to exposure to infected blood. Vaccination for the hepatitis B virus (HBV) is highly essential, as the virus can survive for seven days outside the body and can affect non-vaccinated individuals.

Clinical Findings of Hepatitis B Virus (HBV):

• Jaundice (change in the color of eyes and skin).

• Increased fatigue.

• Nausea and vomiting.

• Dark-colored urine.

• Abdominal pain.

• Causing liver cancer.

Treatment of Hepatitis B Virus (HBV):

• Medications, which include oral antiviral drugs.

• The life expectancy of the individual can be increased by early detection of the hepatitis B virus (HBV) and undergoing treatment such as chemotherapy and surgeries, including liver transplantation, which can be needed in some instances.

What Is Human T Lymphotropic Virus 1 (HTLV1)?

Human T lymphotropic virus one (HTLV1), also called human T cell leukemia type 1, is usually transmitted through infected cells containing bodily fluids like breast milk, blood, and semen. However, it can also be transmitted by direct contact.

Clinical Findings of Human T Lymphotropic Virus 1 (HTLV1):

Usually asymptomatic, but in a few cases, symptoms can be detected.

• Hepatosplenomegaly.

• Lymphadenopathy.

• Myelopathy.

• Muscle weakness.

• Hyperreflexia.

• Bladder dysfunction.

• Lower back pain.

Treatment of Human T Lymphotropic Virus 1 (HTLV1):

No treatment is recommended for asymptomatic patients. The entire treatment is symptom-based.

What Is the Hepatitis C Virus (HCV)?

Hepatitis C virus (HCV) is a blood-borne virus caused by inadequate sterilization of hospital equipment, such as needles and syringes. It can also be spread from parent to child but is not transmitted through breast milk, casual contact, or sharing food with the infected person.

Symptoms of the Hepatitis C Virus (HCV):

• Fatigue.

• Fever.

• Decreased appetite.

• Abdominal pain.

• Nausea and vomiting.

• Joint pain.

• Dark urine.

• Jaundice.

Treatment of Hepatitis C Virus (HCV):

Antiviral drugs, which include Sofosbuvir and Daclatasvir, are administered.

There is no effective vaccination for the hepatitis C virus (HCV), so prevention is a better cure.

What Is Merkel Cell Polyomavirus(MCPyV)?

Merkel cell polyomavirus (MCPyV) is a common virus infecting humans and was recently discovered. It is detected in various anatomical locations, most commonly on the skin.

Clinical Findings of the Merkel Cell Polyomavirus (MCPyV):

• Neuroendocrine cancer.

• Merkel cell carcinoma.

• Skin lesions.

What Is Kaposi Sarcoma-Associated Herpes Virus (KSHV)?

Kaposi sarcoma-associated herpes virus (KSHV), also known as human herpes virus 8 (HHV8), occurs commonly in HIV (human immunodeficiency virus) individuals.

Symptoms of Kaposi Sarcoma-Associated Herpes Virus (KSHV):

• Fatigue.

• Fever.

• Lymphadenopathy.

• Splenomegaly.

• Cachexia.

• Gastrointestinal symptoms.

• Respiratory symptoms.

Treatment for Kaposi Sarcoma-Associated Herpes Virus (KSHV):

• Surgical therapy.

• Chemotherapy, including antiviral drugs such as Ganciclovir.

• Radiation therapy.

What Are the Tumors Caused by Oncogenic Viruses?

The following are the tumors caused by the oncogenic virus:

• Hepatocellular Carcinoma - It is a common cancer affecting the liver.

• B-Cell Lymphoma - B cells are part of the immune system. Cancer that occurs in B cells is called B-cell lymphoma.

• Gastric Carcinoma - Cancer of cells lining the stomach wall is termed gastric cancer.

• Nasopharyngeal Carcinoma - Cancer of the nasopharynx region is called nasopharyngeal carcinoma.

• Cervical Carcinoma - The cervix is a part of the female reproductive system. The uncontrolled growth of cancer cells in that region of the cervix is termed cervical carcinoma.

• Head and Neck Cancer - Cancers occur in the head and neck regions.

How Do Oncogenic Viruses Cause Tumors?

Various studies have been carried out to determine the mechanism by which tumors occur. The following are a few reasons for cancer caused by viral oncogenes.

• Viral proteins (proteins produced by viruses) specifically denote the presence of specific genes that cause cancer.

• Host cell alterations and genomic instability lead to cancer.

• Sharing host cell targets.

• Targeting host signaling pathways.

• Targeting tumor suppressor pathways.

• Manipulation of host immune response.

Can Oncogenic Viruses Alone Cause Cancer?

Not all oncogenic viruses cause cancer. Most of them alter genes, causing normal functioning by inserting a foreign viral genome into the host gene. Such alterations lead to the uncontrolled growth of cancer cells, leading to tumors.

Conclusion

Viral infections are diseases that most people are afraid of contracting. Cancers caused by viral infections appear even more dangerous, and most of the human population is unaware of them. It is necessary to consult a physician to diagnose the condition correctly and obtain a treatment plan. Whether it is always noted in the case of viral infections, prevention is better than cure.