Stage 1 Colon Cancer

What is stage 1 colon cancer?

Stage 1 colon cancer is considered early-stage colon cancer, which means the tumor is small and localized to the final part of the large intestine, known as the colon. Due to its proximity to the rectum and similarities to rectal cancer, colon cancer is also known as colorectal cancer (CRC). [¹] [²]

In this early stage, the cancer is generally in the form of a colon polyp. This growth projects from the intestinal wall. The two most common polyps that become cancerous are hyperplastic polyps. [³]

What are the subtypes of stage 1 colon cancer?

Subtypes of stage 1 colon cancer are defined by their origin. If cancer starts in the colon, it is colon cancer, but if it originates in the rectum, it is rectal cancer.

95% of colon cancers are adenocarcinomas that start in the colon's mucus lining. Within this category, the most prevalent are mucinous adenocarcinomas and signet ring adenocarcinomas. [²][⁴][⁵]

Other subtypes of colon cancer are listed below:

Carcinoid tumors
Primary colorectal lymphomas
Gastrointestinal stromal tumors
Leiomyosarcomas
Melanomas

Stage 1 colon cancer staging and diagnosis

Colon cancer staging

In general, the TNM system is used to describe and classify cancers, including colon cancer, where:

T (tumor) describes the size and location of the tumor
N (nodes) indicates whether or not it has spread to nearby lymph nodes
M (metastasis) describes if and how far cancer has spread from its origin

How common is stage 1 colon cancer?

Colon cancer is the 4th most common cancer diagnosed in the US, with 151,030 new cases in 2022. Still, it only represents 7.9% of all new cancer cases. Stage 1 colon cancer is diagnosed in 37.2% of new cases. [⁷]

Men are at a higher risk of colon cancer than women for colon cancer; African American men have the highest incidence, estimated at 52.4 cases per 100,000. Additionally, colon cancer does not seem to have a genetic factor, with 75- 90% of cases lacking a genetic link. [⁸]It is considered a late-age disease, seen most in individuals above 65, with a median age of 66. [⁷]

In the past two decades, the incidence rate for colon cancer has decreased by 2% thanks to better screening tests; however, new cases are rising in adults under 50 by 1.5%. [⁹]

How is stage 1 colon cancer diagnosed?

As stage 1 colon cancer does not have any symptoms, it is generally diagnosed through a routine screening test.

Stage 1 colon cancer screening tests

Screening a pick at an early stage grows better than any other diagnostic method, which is why the American Cancer Society recommends over the age of 45 have regular screening tests. African American men are advised to start at 40. [¹⁰]

Screening tests for stage 1 colon cancer include:

Colonoscopy: a thin, flexible tube camera, called a colonoscope, is inserted in the rectum to examine the entire colon. Abnormal growths such as polyps will be visible in a colonoscopy.
CT colonoscopy: A less invasive version of a colonoscopy that takes images of the colon to find abnormalities
Sigmoidoscopy: Similar to a colonoscopy, this procedure only checks the lower portion of the colon, known as a sigmoid colon.
Stool DNA test: laboratory examination of a stool sample can reveal changes in DNA or blood that may indicate colon cancer

Stage 1 colon cancer diagnostic tests

If screening tests reveal an abnormality or the patient experiences any of the symptoms of colon cancer, doctors do a full panel of diagnostics tests which include:

Medical and family history to determine how at risk a patient is for colon or rectal cancer.
A physical exam includes a digital rectal exam (DRE). In a DRE, a doctor feels for any unusual growth inside the rectum by inserting a gloved, lubricated finger.
Diagnostic colonoscopy: Just like a screening colonoscopy, doctors will check the length of the large intestine for abnormalities. If any suspicious growths are detected, doctors can take a biopsy or, if possible, remove it completely with special medical instruments that pass through the colonoscope.
Biopsy: usually done during a colonoscopy, a biopsy removes a small tissue sample from an area of the colon that doctors suspect is cancerous.
Stool tests for health conditions such as anemia can also produce abnormal results. Common tests include: fecal occult blood test (FOBT) and fecal immunochemical test (FIT)
Blood tests: Blood samples are taken to check for any discrepancies that could indicate cancer has spread. These include: Complete blood count (CBC), Liver enzymes, and Presence of certain tumor markers, such as carcinoembryonic antigen (CEA)

Stage 1 colon cancer symptoms

Many patients with stage 1 colon cancer don’t experience symptoms as the growth is too small to cause systemic changes. [⁶]If symptoms do present, the most common are listed below:

Persistently changing bowel movements from constipation to diarrhea
Changes to the stool consistency
Blood in stool
Rectal bleeding
Abdominal pain
Abdominal discomfort includes gas and cramps
Fatigue
Weakness
Changes in appetite
Unexplained weight loss

Stage 1 colon cancer treatment

The treatment for stage 1 colon cancer depends on certain factors, including the extent of the disease and the grade of the cancer cells. Furthermore, the patient's general health is also vital to consider, as certain treatment options may not be tolerable.

A multidisciplinary team collaborates to develop individualized treatment protocols for each case. This team includes a gastroenterologist, surgical oncologist, colorectal surgeon, radiologist, and an oncology dietitian.

Stage 1 colon cancer first-line treatment

Stage I colon cancers are deep, within the layers of the colon wall, but have not spread out to surrounding tissue or lymph nodes. This localization makes it easier to treat and remove completely. [⁶][¹¹]

Local excision

Local excision is only done if the cancer is localized, such as inside a polyp with no cancer cells at its margins (i.e. well differentiated). This minimally invasive technique is via a colonoscope. While no other treatment is necessary, doctors will continue actively monitoring the colon to check for any new growths every 3 months for the first 2 years, followed by every 6 months. [¹¹] [¹²]

Resection

If the tumor does not have well-defined edges, a reaction is needed to remove the growth and part of the healthy tissue surrounding the growth. Resection is an invasive surgery that can be done via a long incision in the abdomen or laparoscopically. It is also called a partial colectomy. Generally, additional treatment is not required, but the area is actively monitored.

Adjuvant chemotherapy or radiation therapy

After a local excision or resection, if there is a suspicion that cancerous cells have spread to surrounding tissue, doctors will recommend a course of chemotherapy or radiation therapy. While these two options are generally not primary treatments, they may be recommended as a first-line treatment for patients who cannot tolerate the stress of any surgical procedure.

Other types of treatment for stage 1 colon cancer

Pelvic exenteration

If cancerous polyps are more widespread within the colon or spread to the rectum and beyond, pelvic exenteration may be needed. This procedure removes the lower portion of the colon, the rectum, and the bladder. Men may also need to have their prostate gland removed, while women may need their ovaries, fallopian tubes, and vagina removed.

To allow stool to be passed out of the body after such an extensive procedure, surgeons create an opening in the body known as a stoma in a procedure known as a colostomy. The stoma allows excretions to exit the body and be collected in an external bag.

Cryosurgery

Stage 1 colon cancer patients who are unable to undergo invasive surgery can opt for cryosurgery, which aims to kill cancer cells by freezing using freezing argon gas or liquid nitrogen. Surgeons use precise needle-like instruments called cryoprobes to target cancerous cells. The immune system then removes these dead cells in a process called efferocytosis.[¹³]

Radiofrequency ablation (RFA)

RFA is another less invasive surgical option. Surgeons insert tiny electrodes into cancerous cells, which pass an electrical current. This stimulation hyper agitates the cells causing them to die. The immune system removes these dead cancer cells. [14]

Can stage 1 colon cancer be cured?

When asking, “can stage 1 colon cancer be cured” it is important to first factor in the tumor's location. If it is still within the walls of the colon, it may be removed completely, but there is always a chance of remission. Therefore long-term management is necessary to minimize symptoms.

However, if the colon cancer has spread beyond the colon into lymph nodes or other parts of the body, it is difficult to cure, and even if a patient goes into remission, recurrence is high.

Prognosis: Stage 1 colon cancer survival rate

As with treatment, the prognosis for stage 1 colon cancer depends on the patient's health and the specifics of their cancer. The prognosis for stage 1 colon cancer is much more favorable than that for later stages.

Prognosis usually deals with two separate metrics: survival and quality of life (QOL).

Survival is measured by the five-year survival rate, which indicates the percentage of patients alive five years after their initial diagnosis.
Quality of life considers the ability of a patient to continue living a healthy and enjoyable life with regard to the status of their cancer and the medical interventions they are dealing with.

For a prognosis chart of colon cancers in general, including stage 1 cancer, refer to [⁷].

Stage 1 colon cancer survival rate

The five-year survival rate for stage 1 colon cancer is promising. As diagnostics methods and treatments improve, this rate is slowly increasing. The five-year survival rate for stage 1 colon cancer is 90.9% of cases, meaning approximately 90 out of every 100 stage 1 colon cancer patients survive the first five years after initial diagnosis. [⁷].

If cancer spreads to the surrounding tissue, the five-year survival is still relatively favorable at 72%. However, if it spreads to distant parts of the body, the rate drastically drops to 15%. [⁶]

Stage 1 colon cancer recurrence rate

Stage 1 colon cancer that is contained within the lining of the colon has an estimated 5% risk of recurrence after surgery. [¹⁵]

Stage 1 colon cancer growth rate

Typically, stage 1 colon cancer is slowly growing, gradually spreading through the colon wall to the rest of the body. However, it is also possible for the cancerous cells to reach a lymph node before making it through the intestinal wall. [⁴]

Lifestyle changes for preventing and managing colon cancer

Those at a higher risk of developing colon cancer include the elderly with a family history, inflammatory bowel disease (IBD), or adenomas in the colon. However, several external factors can also further increase their colon cancer risk.

Researchers continue to study these to find links to colon cancer and use this information to find prevention methods. Although there is still no definitive way to fully prevent colon cancer, certain lifestyle changes may lower the risk. These are listed below:

Regular screenings allow doctors to look inside the colon and remove growths, such as polyps, that can become cancerous.
Taking Aspirin or any other NSAIDs (nonsteroidal anti-inflammatory drugs). Some research suggests that these drugs can reduce polyp development in people with a family history of polyps or colorectal cancer, or polyps. However, this is not conclusive evidence, and this measure needs to be discussed with a doctor. [¹⁶] [¹⁷]
Obesity increases the risk of colon cancer; therefore, it is important to maintain healthy body weight. Evidence links higher body weight with a higher risk of developing colorectal cancer. Eating well is one of the best ways to improve your health and reduce cancer risk. This can help you maintain your body weight or lose weight if necessary. [¹⁸] [¹⁹]
Consuming a healthy diet low in red meat and rich in whole grains, vegetables, and fruits has been suggested to reduce incidences of colon cancer. Further studies suggest regular vitamin D and calcium supplements may lower the risk. [²⁰]
Increased water intake has been linked to decreasing the risk of polyp development [²¹]
Stop smoking and reduce alcohol consumption. [²²]
Regular exercise can lower the risk of colon cancer. Doctors recommended 150 – 300 minutes of moderate to intense physical activity per week while reducing sedentary behavior such as lying, sitting, and screen-based activities. [²³]

Conclusion

Takeaways

In the US, colon cancer is the second deadliest cancer, with 52,580 deaths estimated in 2023 [⁶]. A major focus of clinical research is to develop better, less invasive screening and diagnostic methods to catch the cancerous cells in the colon as early as possible.

Stage 1 colon cancer is a highly treatable condition with a promising prognosis, so regular screening and early intervention are the best long-term survival and quality of life for colon cancer patients.

While the appropriate treatment plan is highly individual, local excision or surgical resection of part of the colon, with possible adjuvant radiotherapy or chemotherapy, is most common.