How Fast Does Melanoma Spread?

Melanoma is a deadly form of skin cancer because of its ability to metastasize to local lymph nodes and other organs.  It is estimated that melanoma kills, on average, over 10,000 people in the United States every year.

The first sign of flat melanoma is usually a new spot or an existing mole or freckle that changes in appearance. Some changes can include:

  • A spot that has grown in size
  • A spot where the edges are looking irregular versus smooth and even
  • A spot that has a range of colors such as brown, black, blue, red, white or light gray.
  • A spot that has become itchy or is bleeding

According to Dr. Andrew Duncanson, board-certified dermatologist at Forefront Dermatology, “It is important to know that melanoma can appear on areas of the skin not normally exposed to the sun such as under the arm, chest, and buttocks. It can also appear in areas that you are not able to see easily on your own including the ears, scalp, back of legs, and bottom of feet. I always recommend to my patients to look for the ugly duckling spot – the new spot that doesn’t look like any others. Additionally, ask a family member to look over the hard to see areas monthly, while also getting an annual skin cancer exam by a board-certified dermatologist to detect skin cancer early.”

How fast does melanoma spread and grow to local lymph nodes and other organs? “Melanoma can grow extremely quickly and can become life-threatening in as little as six weeks,” noted Dr. Duncanson. “If left untreated, melanoma begins to spread, advancing its stage and worsening the prognosis.”

A melanoma in its earliest stages is localized, meaning the malignant cells have not multiplied to the point that they extend beyond the skin. The very earliest melanomas (stage 0) do not extend past the top layer of the skin, the epidermis. This type of melanoma I s called in situ, a Latin phrase that means “in original position,” and they are considered noninvasive. If the malignant cells penetrate deeper, into the dermis, it is considered invasive (stages I and II). On average, the estimated five-year survival rate for melanomas detected while still localized is very high, about 98 percent in the U.S.

As the malignant cells begin to spread into the lymph nodes, the cells can be carried beyond the original site into other organs, including ones far away from the original site. Once melanoma has spread beyond the original site either en route to the lymph nodes or in the actual lymph nodes already, it is considered a stage III melanoma. The five-year survival rate then drops to around 62 percent because of the high risk that cancer can spread from the nodes throughout the body.

When the malignant cells have successfully made their way into the lymph nodes and have reached further body sites, such as organs, it is considered a stage IV melanoma. Stage IV melanoma, unfortunately, has an estimated five-year survival rate of only 18 percent in the United States. These survival figures are improving every year because of early detection and new treatments becoming available.

When it comes to stopping melanoma in its tracks, early detection is key and can truly mean the difference between life and death. Skin cancer exams are a 10-minute appointment where your board-certified dermatologist will thoroughly exam your body for any unusual spots. This is the time for you to point out any spots that you have noticed as new or changing. Find a dermatologist near you and schedule your annual exam today!