Some bowel cancer patients whose disease has spread to the liver are being denied potentially life-saving surgery, new research shows.
More than 40,000 people are diagnosed with bowel cancer every year and the disease spreads to the liver in about half of cases.
The new study, funded by Cancer Research UK, found only a fifth of patients were referred to liver specialists.
Published in the British Journal of Surgery, experts examined rates of liver surgery in Yorkshire.
Referral rates varied widely between the seven hospitals in the area. While one referred 43% of patients to see liver specialists, another referred 13%.
The research was carried out by experts at St James's University Hospital, Leeds, and looked at the treatment of more than 600 patients with bowel cancer that had spread to the liver.
Of the fifth referred in total, three-quarters were deemed to be fit for liver surgery.
The study found worrying signs that some doctors did not think patients were fit for surgery when in fact they were.
Patients whose bowel specialists decided they should not undergo a liver operation, despite being fit for surgery, were reassessed by liver specialists.
In 44% of cases the liver specialists disagreed.
All patients are seen by bowel cancer specialists, who can refer them to liver specialists if they think they may benefit from liver treatment.
The most common treatment is surgery to remove tumours from the liver - which may help cure the patient.
Alastair Young, study author and surgical registrar at St James's, said: "Bowel cancer specialists are deciding whether or not a patient is suitable for liver surgery.
"We're seeing liver specialists disagree with the decision in almost half of cases, meaning that some patients are denied an operation that could save their lives.
"One of the striking things about this work is that our region has been shown to have the highest rates in the country of liver surgery for bowel cancer patients.
"But we've shown a significant gap between current and best practice in our region, suggesting there is plenty of room for improvement up and down the country.
"These decisions are not made lightly but liver and bowel specialists need to talk to each other much more to ensure every patient has the best possible chance of beating the disease and to reduce the worrying difference in referral rates."
Professor Peter Johnson, Cancer Research UK's chief clinician, said: "This shows how important it is for cancer specialists to collaborate when discussing treatment so all patients can benefit from their collective medical expertise.
"The patient's welfare is key so the benefits of surgery must be weighed against the risks.
"Not all patients will be eligible for these operations because their cancer may be too advanced, they may have other health problems or they may not want to have surgery."
Bowel cancer is the fourth most common cancer in the UK.
Around 40,700 people were diagnosed with bowel cancer in 2010 - around 110 people every day.
It is the second most common cause of cancer death in the UK after lung cancer, killing around 15,700 people in 2010 - around 43 people every day.
Sean Duffy, national clinical director for cancer at NHS England, said: "This study shows how important it is for organisations to communicate effectively with each other.
"The role of liver surgery in treating colon or bowel cancer which has spread to the liver speaks for itself, enabling patients who have been carefully selected for their suitability for this treatment to live longer.
"For this reason, it is very important that the multi-disciplinary team where the diagnosis is made communicates well with the specialist liver team and vice versa.
"Clear referral guidelines are required to aid this activity."