For a while I am observing that Muslim singers/actors in my country are suffering from various forms of cancers.
Can there be any explanation from Islamic perspective?
Or, am I just trying to connect the disconnected dots here?
You may be reading too much into the situation.
It could very well be a form of punishment for a sin (I am making the assumption here that the singers and actors you are referring to get involved in works that are not permissible Islamically) as Allah ﷻ has informed us that punishment for our bad deeds may be brought forward to this world:
وَمَا أَصَابَكُم مِّن مُّصِيبَةٍ فَبِمَا كَسَبَتْ أَيْدِيكُمْ وَيَعْفُو عَن كَثِيرٍ
And whatever strikes you of disaster — it is for what your hands have earned; but He pardons much.
While the first possible reason for their cancer may be punishment, the second reason may be to elevate one's rank:
قال إبراهيم بن مهدي السلمي - عن أبيه عن جده، وكانت له صحبة من رسول الله صلى الله عليه وسلم، قال سمعت رسول الله صلى الله عليه وسلم يقول: إِنَّ الْعَبْدَ إِذَا سَبَقَتْ لَهُ مِنَ اللَّهِ مَنْزِلَةٌ لَمْ يَبْلُغْهَا بِعَمَلِهِ ابْتَلاَهُ اللَّهُ فِي جَسَدِهِ أَوْ فِي مَالِهِ أَوْ فِي وَلَدِهِ
Narrated Muhammad ibn Khalid as-Sulami: on his father's authority said his grandfather reported: He was a Companion of the Messenger of Allah (ﷺ) said: "I heard the Messenger of Allah (ﷺ) say: When Allah has previously decreed for a servant a rank which he has not attained by his action, He afflicts him in his body, or his property or his children."
This forthbringing of the punishment may actually be a good sign in a way:
قال رسول الله صلى الله عليه وسلم: إذا أراد الله بعبده خيراً عجل له العقوبة في الدنيا، وإذا أراد الله بعبده الشر أمسك عنه بذنبه حتى يوافي به يوم القيامة
The Messenger of Allah (ﷺ) said, "When Allah intends good for His slave, He punishes him in this world, but when He intends an evil for His slave, He does not hasten to take him to task but calls him to account on the Day of Resurrection."
قال النبي صلى الله عليه وسلم: إن عظم الجزاء مع عظم البلاء، وإن الله تعالى إذا أحب قوماً ابتلاهم، فمن رضي فله الرضى، ومن سخط فله السخط
The Prophet ﷺ said: "The greatest reward comes with the greatest trial. When Allah loves a people He tests them. Whoever accepts that wins His pleasure but whoever is discontent with that earns His wrath."
So, their illness may be a punishment or may be a test to see how they would endure it, or it may be to expiate their sins or to elevate their status. Only Allah knows. This is not to be taken that Islam endorses any impressible acts, but the interpretation of calamities that befall us is not the kind of knowledge that Allah has revealed to us at all times.
You may refer to Islam Q&A's article "How can one who is afflicted with calamity know whether it is a punishment or a test to raise him in status?" for more information.