Bowel cancer spread to the liver: what is life expectancy after liver surgery?

How often does bowel cancer spread to the liver?

Bowel (colorectal) cancer is the third most common cancer worldwide. In Australia about 15,000 people are diagnosed each year, it accounts for nearly one in ten new cancer diagnoses, and the lifetime risk by age 85 is about 1 in 21. Screening has cut the age-adjusted rate by a third since 2001, while population growth and ageing keep the total number of cases steady.

About half of people with bowel cancer have or develop spread (metastases), most often to the liver. Liver resection offers the only potential cure, and for carefully selected patients with favourable tumour biology, no spread outside the liver and enough healthy liver left after surgery, five-year survival of 40% to 60% is achievable.

How has treatment for liver metastases changed over 20 years?

Chemotherapy has moved from fluorouracil alone to combinations with oxaliplatin or irinotecan (FOLFOX and FOLFIRI), with better response rates and survival. Targeted drugs followed: bevacizumab, which blocks blood vessel growth, and cetuximab and panitumumab, which block the EGFR receptor in tumours without RAS mutations. In some patients these shrink tumours enough to make inoperable disease operable.

Surgery has expanded too. Portal vein embolisation grows the healthy side of the liver before surgery, two-stage hepatectomy and ALPPS allow very extensive disease to be removed in steps, and keyhole and robotic liver surgery shorten recovery. Liver-directed treatments such as radiofrequency and microwave ablation, chemoembolisation (TACE) and selective internal radiation therapy (SIRT) add options for local control.

Who had liver surgery in this study?

Every patient was staged with a multiphase CT and a PET scan, with MRI added routinely from 2015, and every treatment plan went through a multidisciplinary team. Surgery was offered when all the disease could be removed with a clear margin while leaving enough liver to function.

The median age was 65 and 63% were men. In 29% the original cancer was on the right side of the bowel, and in 53% the liver spread was found at the same time as the bowel cancer. Most patients (71%) had chemotherapy before surgery, usually an oxaliplatin combination, and 22% also had a targeted drug, mostly bevacizumab.

What are the survival and recurrence rates after liver resection?

With a median follow-up of more than ten years, more than half the patients were alive at five years and one in three at ten years. The disease came back in 70%, and 43% had a recurrence within the first year. Recurrence within 12 months carried a much higher risk of death than later recurrence, and the timing of any recurrence is one of the strongest signals of how the disease will behave.

Recurrence does not end the options for treatment. Thirty-two patients had a further liver resection with curative intent for recurrent disease, and the authors suggest that active treatment of recurrence may explain why long-term survival in this cohort was higher than the long-term disease-free rate.

What affects life expectancy after liver surgery for bowel cancer?

Several factors independently predicted survival. Each decade of age raised the risk of death by 24%, although the authors note other studies find biological fitness matters more than age in years. A right-sided primary cancer raised the risk by 46%, which fits with right-sided tumours carrying RAS and BRAF mutations far more often (90% compared with 40% of tested tumours). Each extra 5 mm in the largest liver tumour added about 5%.

Having more than three liver tumours and having a complication after surgery both had a large effect early on that faded over the years. Among tested tumours, RAS and BRAF mutations were also linked with poorer survival, which is why molecular testing is now part of routine treatment planning.

Why did chemotherapy appear linked to worse survival?

Patients who had chemotherapy without a targeted drug, before or after surgery, had poorer survival in this analysis. The authors explain that this almost certainly reflects who received treatment: people with more tumours, more aggressive biology or early recurrence are the ones offered more chemotherapy, and a retrospective study cannot fully adjust for that.

A similar pattern appeared in the New EPOC trial, where adding cetuximab to chemotherapy for operable liver metastases worsened progression-free survival, suggesting some patients may be over-treated. Current European guidelines now limit cetuximab to left-sided RAS wild-type tumours, and earlier use of targeted drugs in this cohort was less selective. The practical message is that chemotherapy decisions belong with a multidisciplinary team that weighs tumour biology for each person.

How do these results compare with other liver surgery centres?

Ten-year survival of 33% sits alongside other published long-term series: 18% in a multicentre cohort that included patients with disease outside the liver, 21.8% across three UK centres, 22% at Memorial Sloan Kettering Cancer Center in New York, and 22.3% in a recent Argentinian series. Across these studies, long-term cure without any recurrence is achievable in about one patient in ten.

Ablation and other liver-directed treatments were used in a minority of patients here, mostly for recurrence. Trials such as COLLISION, which found similar survival with ablation or resection for small liver metastases, support choosing between these options case by case.

What are the limits of this study?

This was a retrospective analysis of one centre's patients over 20 years, during which chemotherapy, targeted drugs and imaging all changed, and molecular testing only became routine from 2010. Those changes make it hard to isolate the effect of any single treatment. Its strength is rare ten-year follow-up from Australian multidisciplinary practice, which gives patients and doctors a realistic local benchmark.