Like many forms of cancer, the outlook for people with colorectal cancer (CRC) has improved as our understanding of the disease has increased.

In the early stages of CRC, there are now a range of treatment options available and as a result survival rates have improved significantly over the past 20 years.1 Yet for those with advanced disease who don’t respond to earlier lines of therapy, the options are limited. In fact, for people whose disease has progressed after receiving two rounds of treatment, nearly half in Europe and in the US will receive no further treatment at all.2,3 This may be due to the limited options for third-line treatment,4 coupled with poor overall survival from second to third line treatment.5

Early symptoms of CRC can include abdominal pain and blood in bowel movements, although these can easily be confused with those of other diseases, such as Irritable Bowel Syndrome, Crohn’s disease or peptic ulcers.6

Colorectal cancer represents a considerable burden to society 7

CRC represents a considerable burden to society
CRC represents a considerable burden to society

Although advances in screening have reduced mortality, 20% of people with CRC have metastatic disease at initial diagnosis.8,9 This means that their cancer has spread to other parts of the body, making treatment more complicated and their prognosis worse.10

New treatment options for advanced colorectal cancer are needed

Initial treatment for CRC typically consists of a chemotherapy either administered alone or in combination with a biological therapy.1 However, for those people with advanced CRC – whose cancer has progressed on other treatments – the options are far more limited.11 In fact many people at this stage receive no treatment at all.

Checkpoint inhibitors, a type of immunotherapy that can kick start the immune system into fighting cancer, have recently emerged as a treatment option for a small subset (3-5%) of people with advanced CRC. People with these tumours have a biology described as “microsatellite instability-high” (MSI-H), which increases the likelihood that the body’s own immune system is able to detect the tumour.12

Treatment options vary according the subtype of CRC
There is a huge disparity in the incidence of MSS and MSI-high CRC, treatment options also vary according to the subtype.

The remaining group, accounting for around 95% of people with advanced CRC, has disease commonly described as “microsatellite stable” (MSS). For these people the immune system is most often not able to engage with the tumour and monotherapy checkpoint inhibitors have currently not been shown to be effective. With this in mind, researchers are now exploring how they could expose CRC to the immune system by designing combination treatments that trigger an immune response.

Stefanie Srock, Group International Medical Director at Roche, said: “It is clear that for people with advanced colorectal cancer their treatment options are limited. In fact, many receive no treatment at all which can lead to their health deteriorating rapidly. New treatments are desperately needed to improve the lives of people living with advanced colorectal cancer.”

Research continues to address this medical need in advanced colorectal cancer.

References

  1. Van Cutsem E, et al. ESMO consensus guidelines for the management of patients with metastatic colorectal cancer. Annals of oncology: official journal of the European Society for Medical Oncology. 2016;27(8):1386-422.
  2. Tampellini M, et al. Treatment of Patients with Metastatic Colorectal Cancer in a Real-World Scenario: Probability of Receiving Second and Further Lines of Therapy and Description of Clinical Benefit. Clin Colorectal Cancer. 2017; 16(4) 372–376.
  3. Abrams TA, et al, Chemotherapy usage patterns in a US-wide cohort of patients with metastatic colorectal cancer. J Natl Cancer Inst. 2014; 106(2):djt371.
  4. Carter NJ, et al. Drugs Aging. 2014; 31(1):67–78.
  5. Hanna N, et al, ASCO GI. 2014 (https://meetinglibrary.asco.org/record/89612/abstract)
  6. John SKP, et al. (2011), Symptoms and signs in patients with colorectal cancer. Colorectal Dis. 13: 17–25.
  7. Ferlay J, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int. J. Cancer. 2015;136(5): E359-86.
  8. Riihimaki M, et al. Patterns of metastasis in colon and rectal cancer. Scientific reports. 2016;6:29765.
  9. Shahidi N, Cheung WY. Colorectal cancer screening: Opportunities to improve uptake, outcomes, and disparities. World J Gastrointest Endosc. 2016;8(20):733-40.
  10. Henley SJ et al. Surveillance of Screening-Detected Cancers (Colon and Rectum, Breast, and Cervix) --- United States, 2004—2006. MMWR Surveill Summ. 2010 59(9):1-25.
  11. Yang Q, et al. Bevacizumab plus chemotherapy as third- or later-line therapy in patients with heavily treated metastatic colorectal cancer. Onco Targets Ther. 2015; 8:2407–2413.
  12. Overman MJ et al. Nivolumab in patients with metastatic DNA mismatch repair-deficient or microsatellite instability-high colorectal cancer (CheckMate 142): an open-label, multicentre, phase 2 study. Lancet. 2017 Sep;18(9):1182-1191.