SPARC is at the forefront of treating early cancers of the gastrointestinal tract.
We provide expert care for early cancers and predisposing diseases of the gastrointestinal tract.
A new diagnosis of an early gastrointestinal cancer or a disease that predisposes a patient to cancer is a significant life event. Our SPARC physicians are committed to patient-centred, sub-specialty care.
SPARC physicians are well versed in and see many patients with early cancers of the gastrointestinal tract. Every patient presentation is unique. For complex conditions, we use multidisciplinary conferences to ensure the best outcomes for our patients.
Large colorectal polyps and early colorectal cancer
Colorectal cancer (CRC) is a significant global health concern. It is the third most commonly diagnosed cancer and the second leading cause of cancer-related death worldwide. By 2030, the global burden of CRC is projected to increase by 60%, highlighting the critical role of the colonoscopy in both the early detection of CRC and its prevention through the removal of polyps—growths on the inner lining of the colon and rectum.
During a colonoscopy, the majority of polyps are small, have a low risk of cancer and are easily removed using standard polypectomy techniques. However, approximately 8% of patients undergoing colorectal cancer screening will have a large polyp (≥ 20 mm) identified. Large polyps are more complex to remove and carry a higher risk of malignancy. While they can sometimes cause symptoms such as rectal bleeding, changes in bowel habits (constipation or diarrhea), abdominal pain or iron deficiency anemia, most are asymptomatic and discovered incidentally during a colonoscopy.
Historically, large polyps were removed surgically. Today, however, minimally invasive endoscopic resection techniques are the first-line treatment for most large polyps, as recommended by both North American and European guidelines. These techniques have demonstrated strong safety and effectiveness. Current methods include:
- Endoscopic mucosal resection (EMR)
- Endoscopic submucosal dissection (ESD)
- Cold snare resection (CSR)
Although most large polyps are benign, some may already contain early-stage colorectal cancer. Fortunately, these cancers can also be effectively treated using minimally invasive endoscopic resection—provided the polyp is removed en bloc (in one piece) to allow accurate pathological evaluation. This assessment ensures there are no high-risk features that would require surgical intervention. Techniques used for the resection of early CRC include EMR and ESD.
Early esophageal cancer
Early esophageal cancer includes two main types:
- Squamous cell carcinoma, more common in individuals of Central and East Asian descent, and associated with smoking and alcohol consumption.
- Barrett’s adenocarcinoma, more prevalent in Caucasian populations, and linked to obesity and chronic gastroesophageal reflux disease (GERD).
Early esophageal cancers can be detected using specialized high-definition endoscopes, often enhanced by virtual chromoendoscopy—a technique that uses light filters to improve visualization. In addition, contrast agents such as iodine and acetic acid may be applied during the procedure to better highlight subtle mucosal changes.
Historically, these cancers and their precursor lesions required surgical intervention. However, advances in minimally invasive endoscopic techniques now allow for effective treatment through the endoscope, including:
- Endoscopic mucosal resection (EMR)
- Endoscopic submucosal dissection (ESD)
When detected early and removed completely, endoscopic resection of esophageal cancer is highly effective, with a low risk of recurrence.
Barrett’s esophagus
When chronic heartburn or acid reflux occurs over many years, some individuals develop changes in the lining of the lower esophagus. This condition is known as Barrett’s esophagus (BE) and is significant because it increases the risk of developing esophageal cancer. As a result, people with BE require regular monitoring to detect early cancerous changes or their precursors.
Risk factors for Barrett’s esophagus include:
- Long-standing heartburn/reflux
- Caucasian ethnicity
- Male sex
- Age over 50
- Obesity
- Smoking
During an upper endoscopy, the normal esophageal lining appears pale, similar to skin. In BE, it changes to a pink, salmon-coloured lining resembling the stomach. If BE is identified, careful inspection is essential to check for nodules (raised areas) or ulcers that may indicate cancer or pre-cancerous changes. Advances in endoscopic imaging—such as narrow-band imaging, chromoendoscopy (special stains), and magnification endoscopy—improve detection of abnormal areas.
After diagnosis, biopsies are taken from the Barrett’s segment to evaluate for dysplasia, the microscopic changes that indicate progression toward cancer. Most patients will have biopsies confirming BE without dysplasia. However, if visible abnormalities or dysplasia are found, referral to a specialist is advised.
In Canada, the treatment of Barrett’s esophagus is offered at specialized centres in each province and may include:
- Endoscopic therapies (radiofrequency ablation, hybrid argon plasma coagulation, cryotherapy)
- Endoscopic mucosal resection (EMR)
- Endoscopic submucosal dissection (ESD)
These minimally invasive techniques allow for effective treatment of Barrett’s esophagus and prevention of progression to cancer.
Early gastric cancer and atrophic gastritis/intestinal metaplasia
Early gastric neoplasia refers to cancer or precancerous changes in the lining of the stomach that are confined to the most superficial layers—the mucosa and submucosa. Due to the high incidence and mortality of gastric cancer in Japan and other Asian countries, the development of techniques for its early detection, treatment and prevention has been a major public health focus.
The most significant global risk factor is infection with Helicobacter pylori (H. pylori), which causes chronic inflammation of the stomach lining. Other contributing factors include family history, autoimmune gastritis and prior gastric surgery.
In the most common form—intestinal-type early gastric cancer—the disease typically progresses through a sequence: chronic gastritis → intestinal metaplasia → low- or high-grade dysplasia → early gastric cancer. The aim is to identify and treat these precursor lesions before cancer develops.
High-definition white light endoscopy, enhanced imaging technologies (such as optical filters) and magnification endoscopy are critical tools for detecting and assessing early stomach lesions.
Endoscopic treatment depends on lesion characteristics such as size and depth, and may include:
- Endoscopic submucosal dissection (ESD)
- Endoscopic mucosal resection (EMR)
When detected early, endoscopic treatment of small gastric cancers is safe, effective, and associated with low recurrence rates.
Achalasia and esophageal dysmotilities
Achalasia is a rare disorder of the esophagus that affects its ability to move food toward the stomach. It is primarily characterized by difficulty swallowing (dysphagia), regurgitation of food, chest pain and sometimes weight loss. The condition occurs when the lower esophageal sphincter (LES)—the muscle at the bottom of the esophagus that normally relaxes to let food enter the stomach—fails to relax properly. Additionally, the esophageal muscles may lose their ability to contract effectively, making it difficult to move food downward.
The exact cause of achalasia is not fully understood, but it is believed to result from degeneration or damage to the nerve cells that control the esophageal muscles.
Diagnosis typically involves:
- Endoscopy, to rule out other causes
- Esophageal manometry, which measures muscle pressures and coordination
- Timed barium swallow, which visualizes how the esophagus handles liquid as the patient swallows
Treatment is tailored to the severity of symptoms, overall health, subtype of achalasia and patient preference. While there is no cure, several effective options can relieve symptoms and improve quality of life:
- Botox injection
- Pneumatic balloon dilation
- Peroral endoscopic myotomy (POEM)
- Surgical myotomy (Heller’s myotomy)
With appropriate treatment, most patients experience significant relief and improved swallowing. However, achalasia is a chronic condition and may require long-term dietary adjustments and follow up. If left untreated or poorly managed, it can lead to complications such as esophageal dilation (megaesophagus), aspiration pneumonia, and, over time, an increased risk of esophageal cancer.
Gastrointestinal polyposis
Gastrointestinal polyposis refers to the presence of multiple abnormal growths, or polyps, in the gastrointestinal (GI) tract—most commonly in the colon and rectum. While some polyps are benign, others carry a risk of turning into cancer, depending on their type. There are several hereditary polyposis syndromes, each defined by the number, type and location of polyps. Individuals with these syndromes have an increased risk of colorectal cancer and, in some cases, other gastrointestinal or non-gastrointestinal cancers.
Polyposis syndromes are typically grouped into three categories:
- Adenomatous polyposis syndromes
- Serrated polyposis syndrome
- Hamartomatous polyposis syndromes
These syndromes are caused by mutations in specific genes, which may be inherited from one or both parents or may arise as new (de novo) mutations with no prior family history. Examples include:
- Familial adenomatous polyposis (FAP): caused by mutations in the APC gene
- Peutz-Jeghers syndrome (PJS): typically caused by mutations in the STK11 gene
- Serrated polyposis syndrome (SPS): a likely hereditary condition, though its genetic basis remains unclear
Most individuals are diagnosed incidentally during an endoscopy or colonoscopy performed for other reasons. These syndromes often do not cause symptoms. Patients diagnosed with polyposis are typically referred to the BC Cancer Hereditary Cancer Program for genetic counselling and testing to identify underlying mutations. If a close family member is affected, targeted genetic testing or endoscopic screening can be used to assess risk.
Management depends on the specific syndrome and may include:
- Referral to the BC Cancer Hereditary Cancer Program for genetic testing, cancer risk assessment and family screening recommendations
- Regular surveillance through endoscopy, colonoscopy and/or small bowel capsule endoscopy (with possible double-balloon enteroscopy) to detect and remove polyps
- Surgical consultation for removal of bowel segments when polyps are too numerous or advanced for endoscopic management
- Multidisciplinary care, including coordination with other specialists to screen for cancers associated with the syndrome
Prognosis varies depending on the syndrome, but with early detection, close surveillance and timely intervention, individuals with polyposis syndromes can often achieve a normal life expectancy.
Hereditary cancer syndromes
Hereditary cancer syndromes are genetic conditions that significantly increase the risk of specific cancers. They often occur at younger ages compared to the general population. Among these, Lynch syndrome, hereditary pancreatic cancer syndrome and hereditary gastric cancer syndrome are of critical importance given their high cancer risk and familial patterns.
Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is caused by inherited genetic mutations in mismatch repair (MMR) genes such as MLH1, MSH2, MSH6 and PMS2. It significantly increases the risk of colorectal cancer as well as endometrial, ovarian, stomach and several other cancers. Individuals with Lynch syndrome may develop cancer at an earlier age and often have a strong family history of associated malignancies.
Hereditary pancreatic cancer syndrome involves genetic mutations such as BRCA1, BRCA2, PALB2 and CDKN2A, among others. A family history of pancreatic cancer, especially when diagnosed before age 50, may suggest a hereditary cause. These mutations not only increase pancreatic cancer risk but may also be associated with breast, ovarian and melanoma cancers.
Hereditary gastric cancer syndrome, particularly hereditary diffuse gastric cancer (HDGC), is most commonly linked to CDH1 mutations. It confers a high lifetime risk of diffuse gastric cancer and lobular breast cancer.
Management depends on the specific syndrome and may include:
- Referral to the BC Cancer Hereditary Cancer Program for genetic testing, cancer risk assessment and family screening recommendations
- Regular surveillance through endoscopy, colonoscopy, endoscopic ultrasound and magnetic resonance imaging (MRI), where appropriate
- Surgical consultation
- Multidisciplinary care, including coordination with other specialists to screen for cancer associated with the syndrome
Prognosis varies depending on the syndrome, but with early detection, close surveillance and timely intervention, individuals with hereditary cancer syndromes can achieve a normal life expectancy.
What our patients have to say about SPARC
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Equitable endoscopy care for underserved patients
Dr. Neal Shahidi is committed to advancing equity in endoscopic care for all British Columbians.
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Successful 2025 CIHR team grant award
The international trial, led by Dr. Daniel von Renteln and joined by Dr. Neal Shahidi, will examine bleeding prevention techniques after large polyp removal.