Janet Jackson recently announced that she had no choice but to cancel her "Unbreakable World Tour", which was supposed to have started on 9 January, as she needed to undergo a vocal chord surgery. It has now come out that doctors have found a tumour that could be cancerous.

On 24 December, late Michael Jackson's sister announced that she needs to cancel her tour, but on 5 January it came out that the doctors have found a potential cancerous growth on her vocal chords.

Janet wrote: "Hey you guys... Happy Holidays to each and every one of you. I need you to know, I learned today, from my doctors that I must have surgery soon. It breaks my heart to tell you that I am forced to postpone the Unbreakable Tour until the spring. Please pray for me, my family and our entire company during this difficult time. There will be no further comment. I love you all so much and am ever grateful for your understanding and your love."

Now, a source has told Radar Online that this medical condition could be serious and needs immediate attention. "Doctors found a growth on Janet's vocal cords that could be serious. It's a medical condition that has to be taken care of immediately," a source close to the "Control" singer told the website.

This is the second time Jackson has postponed her show. Back in October last year, she had taken a medical break to give her voice a rest. But this time it sounds serious. And the source has further said that the singer is feeling positive and will bounce back soon.

"Janet said she knows that with prayers and her will, she'll be back out on the road in the spring or early summer," the source said.

The site has even spoken with Dr Stuart Fischer to get his opinion on this condition and he apparently told the website that if this is cancer of larynx, then it will require surgery C in which patient needs an artificial voice box, just to be able to speak. This could mean that the singer's career could come to an end.

"God forbid that this should be cancer of the larynx which requires surgery C. After this, singing would be impossible. That would abruptly end her ability to ever perform again," said the doctor.

"Surgery would be very complex, and followed by months of radiation treatment," he added.